When it comes to optics, you just can't beat Swarovski.
When it comes to hunting big boars, a good pair of binoculars is essential. Anyone can get lucky when a big boar finally makes a mistake at first or last light, but if you want to consistently kill big boars, you need to learn how to hunt them in the beds in the middle of the day, but you can't do that without good optics.
If possible I do highly recommend a good spotting scope as well. When doing real technical glassing through thick brush, there is nothing better than being able to easily pick apart the hillside and determine quickly if you are looking at the top of a hogs back or just a shadow (trust me after not running one for so many years it will save you a lot of time and miles).
When it comes to any type of big game hunting, I have finally learned that being able to pack an animal out in a frame pack will always beat dragging them or carrying them on your shoulders. For many years I dragged or carried hogs without any type of support. My back was always wrecked after a long weekend. My hunting partner finally talked me into getting a good pack and after going with the Kuiu Pro Hunting Pack, I only wish I had done so sooner. I do believe that I made a mistake by not purchasing the largest bag to go along with it. Take my advice, always get the largest bag possible for your pack. If you don't ever fill it up completely, you aren't losing out, but if you ever need those extra inches, you will be glad you have it.
For the rest of my gear, some other essentials are a good fixed-blade knife. I have broken many foldable and changeable blade knives on the shield of big boars and believe a fixed blade is the way to go, although the trick is to definitely know how to sharpen your knife. There is a local company to me that put out a good lightweight fixed blade this year that utilizes good steel that holds an edge very well. Check out Hogue's new line of hunting knives (even though they are not my favorite, they offer probably the best-designed handle for interchangeable blades as well).
Headlamps are pretty much all in the same. My only advice is to go with something battery powered and not rechargeable. If it ever dies on you at night, you will be glad to just swap out the batteries and not wait for a charge.
My last slick item I have found helpful is a lightweight hatchet (I have a pretty small and sleek SOG). This actually makes breaking down an animal so much quicker than using a saw and saves the blade of my knife as well.
Trekking poles are a must when packing out heavy weight through steep country. It is sometimes a common misconception that we only hunt flat land when hog hunting in California, but I regularly hunt places where I can easily do a 2000 foot elevation climb and especially in the winter you will find yourself on foot more often than not.
I hunt hogs all summer long in the 100+ degree heat and get beat down by the sun, so for us out here in California, sunscreen is a must. Plus being a ginger, the sun and me don't always get along anyways.
Something that is a must-have for any firearm hunting is ear plugs. Take it from a guide who is already wearing hearing aids at the age of 32. I lost the bulk of my hearing due to muzzle breaks and bad hunters over the years and it could have all been saved if I had always been good about hearing protection. You don't think much about it until you lost your hearing. Do yourself a favor and always have hearing protection readily available.
As far as clothing and boots go, I currently run KUIU Clothing almost exclusively.
I have hunted hogs with just about everything imaginable, but rifles are definitely the bread and butter when it comes to hog hunting. The past few years I have gotten into the long range hunting and my partner and myself carry full custom rifles that we often times set our clients up on when we just can't break the distance (first time hunters have knocked hogs over at 500-600 yards easily). When looking to do long range hunting, it is in my opinion that you really should just spend the money and go with a full custom rifle. And when I say this I don't mean to go out and spend 10-12 thousand dollars on a Gunwerks rifle (sorry but in my opinion they are no better than a full custom you can get for half the price). Just get something consistent with enough box mag capacity that you aren't limited on ammunition (also do yourself a favor and stay away from a 6.5 creedmoor).
For a rifle scope I have always been a fan of Leopold.
Now ammo. I'm going to throw out a name you have probably never heard of. McGuire Ballistics Copper Rose. Us out here in California have been forced to shoot non-lead projectiles and me personally, i've been forced in my area for the last 10-15 years. And FINALLY someone produced not only the best non-lead bullet out there, but in my opinion probably the best hunting projectile on the market today. We are talking a lead free bullet that expands as low velocities, leaves huge wound channels, and has BCs just as high as match type bullets. I have watched this company and helped test for them since 2014. These bullets aren't cheap, but this is the only projectile after seeing hundreds of animals shot with them to honestly never have had an animal lost when hit right (actually haven't had a single animal lost yet as of October 2022, but I'm sure our streak will one day end, but the fact that we have had hundreds of animals hit the dirt without loss so far is just mind blowing). Honestly, do yourself a favor and check these out. They were designed and built here in California by a machinist and hunting guide, for hunters. They have killed hundreds of hogs, many deer, some elk, rams, Ibex, African game, etc...
Also check out Hatch bipods. I run them as they are the most versatile hunting bipod I have found to date. I have yet to find an angle I couldn't shoot with off this bipod.