I hunt boar here in Hawaii with bow and arrow, my .357 mag, 12 gauge 00 buckshot, and with the trusty Ruger M77 .270. Only time I'm up in a tree is when using my bow and arrow. Most times I'll figure out where the boar are and find a nice hiding spot at ground level. All of the above listed firearms will do just fine while hunting wild boar.
I hunted boar with a bunch of friends in GA. It was sweet, because at the time we were allowed to "spotlight" them with a light that was powered by 6 volts or less.
Happy hunting!
gf