I have two GP-100's, three Redhawk's in 41,44, and 45 Colt and the 8 3/8" Raging Bull in 454 for big fun.
I have been hunting with handguns for over 25yrs and to be totally honest, I would say pick the bigger caliber. I'm not saying that to boost any manhood, but simply from a downrange performance perspective. Like you mention, you already handload that is plus #1. You also mention picking up casting, plus #2. So you already have runners on two bases and you haven't even walked up to the plate yet.
I use a nice wide nylon belt and holster and carry in a cross draw fashion. It is simply something that has evolved through the years and is quicker for me to clean and get on target that way.
The .357's are nice and light for toting around, but I don't notice my RH's much either. But for hunting you end up loosing powder space when gaining bullet weight. This cuts down on velocity and energy. I understand that if things are perfect that usually isn't a huge factor, but when hunting things are seldom perfect, especially if you are rushed into a shot. (ie. feral hog clearing brush under you feet, or worse working towards clearing your feet from under you.) I have been on both ends of that candle and been burned as well. Heavy bullets even at a moderate velocity trump speed and light weight when things hit the fan.
The 44's are nice as well, I like mine a LOT. I have shot more different loads out of it than probably any other firearm I own. Running top end 180s up through top end 300's in jacketed, and then with lead plodding along at around 900fps up into some which are right there in the mid 1400's. Still with all of that versatility I usually reach for the 41 or 45 when I head out.
If you can find one for around 6-700, the Redhawk in the 7.5" version 45 Colt is really something. You can load pip squeak loads down in the ACP range, or you can load up into the lower 454 range, but you won't need that sort of power so don't even sweat it. Launching a 250 - 280gr WFN cast bullet will drop anything you can draw a bead on, and will shoot from stem to stern on most feral hogs. This is with loads only bumping along at around 1200fps. Of course the 454's are good as well. You CAN drop the loads down using 454 cases into the 45 Colt realm so you don't have to have a supply of both cases on hand. There is a good selection of loads in the Speer manual for the 45-270 SAA cast bullet which is a 270-280gr SWC bullet. Great shooting in both my Colt and my 454. That said though you can adjust the loads to other cast bullets in that weight range for general target use and, well, hunting as well.
Now if you want something that is a real treat, pick up a RH in 41. While it doesn't share the widest available weights in bullets, those which are there work and they work well. For jacketed I usually only use the 200gr Remington SJHP over 20.5grs of 296. This rolls out the muzzle of the 7.5" barrel at around 1300fps and will shoot tighter than I can hold most days. I have dumped plenty of feral hogs in the 80 -200# range with them at ranges measured in feet to out past 100yds. It is a mild recoil with some real authority once it get where it's going. Most top brands make a 170 or 210gr of the two the latter would be my choice. Of the cast selection, if your pouring your own look at Accurate Molds and pick out a nice 215gr WFN or RFN type bullet even maybe one of the SWC styles in that weight range and you will be set. Why would I recommend this one while not in your list? Well it is a somewhat of a sleeper caliber. It has mild recoil when compared to the bigger ones but it doesn't give up much in performance. You might not hit 1800fps with any of the loads, but you don't need to. With the bullets available you get sectional density of a longer bullet. Most of the cast 215's are around the same length of the 240gr 44's. While they aren't quite as big around they still penetrate just as deep and produce some really amazing results all out of proportion to what you would think. Some of my best shots as well as spectacular kills have been with my 41. It just rocks, nuff said. But don't take my word on it check out this thread,
.41 Mag Association
Ok so with that out of the way, I highly suggest that for which ever you choose, you simply get with Starline Brass and pick up a 500ct box of new brass. I also HIGHLY suggest that you pull out and measure 25-30 of them after sizing, and trim to the shortest measured length. This will go a LONG way in keeping your crimps consistent. ( I know I know don't even go there, most folks NEVER trim their pistol or revolver cases, I can hear it now.) Most folks don't shoot 1" groups offhand at 25yds and further with their revolvers either. Trust me it helps. Also don't get caught up in putting too much crimp on your loads either. You only need enough to keep the bullets from moving, and the case tension SHOULD do 95% of the work. I can point you to that in writing as well. Took me nearly a decade to believe it, but once I found it out for myself, I am a true believer now, regardless of the the rest of the world's opinion.
Anyway hope that helps.