Whatever you like. Lots to choose from.
Well, the more traditional lever actions are chambered for lower power cartridges that aren't exactly 200 yard tackdrivers anyway.
If you stay 30-30 or larger bore, you have plenty of options. Most pigs are shot up close, so if you like the bigger bores, absolutely, .44 mag and .45 Colt are just fine. As others pointed out, .357 mag can do it (although I would certainly want to handload for that, since most of the hot stuff won't penetrate tough hogs deep enough to be a good killer without destroying a lot of meat - like a 125gr hollowpoint). The 30-30 will give you something you can shoot deer with in timber.
Personally, I'd go .44 magnum. Yep, full house mag loads in a levergun aren't fun to shoot all day - and the 44 special is pleasant to play with. The .45 Colt is a little better if you're a handloader, but the case rim isn't as large as the .44 and most off the shelf loads aren't really good hunting loads. The .44 mag is much easier to find loads for that are suitable for pigs.
The other calibers aren't going to be quite as much fun. The .45-70 will absolultely kill pigs efficiently, and you can shoot bear and whatnot in timber with it, but it's not going to be something to take to the range and burn a few boxes of ammo. Same deal with something like a BLR in .308 or a (bless you if you find one) Savage 99.
The .30-30 will give you reasonable ammo prices and something that's versatile with off the shelf ammo, as will the .44 mag. For pigs, I'd want to stick with the heavier bullets because they penetrate better, and it's thought by many to be a better short range caliber - and pigs are shot at close range.
I'd go .44 as first choice, 30-30 as second, if I wanted it to double as a deer rifle.
You really do have a lot of choices that are good.
Edit: Oh, hey, Texas - do you mean javelina? They're much smaller than wild pigs (that are real pigs, javelina are not). Ranges for peccary (some people call them Texas pigs, so we may be talking something different) are longer, too. If you mean peccary, I'd go with the .30-30, because the trajectory is flatter and the standard 170-grain .30-30 load, or even better, new pointed polymer tipped bullets, are absolutely lethal on something THAT size. And it gives the old fellow a deer gun for mule deer in Texas.