loaded question...
but i'll take a shot at tryin to help....
to me, and my opinion, handguns are a very personal weapon. if a handgun doesnt feel right to the shooter, its over...dont know if your an archer..but same with a bow grip..
my advice, head to a gunshop...handle every handgun they'll let you...your hand is gunna fall in love with a couple. a couple will stand out that just "feel good" and point naturally...and there will be some that just plain out feel awkward due to thickness, grip angle, grip length, weight of the piece, etc etc...
im not real big on "snake loads" never fired one, but my understanding is after a REALLY short distance they are useless...and even a snake on the ground shooting #11 shot or whatever (i know its super fine shot) im just not real convinced that its gunna do a real good job..could..i dont know..
i dont have snake problems...and honestly, wouldnt kill one that i didnt absolutely need to. a snake that strikes at you got you before your drawing and shooting it...
so my thoughts are forget the snake loads...if you wanna shoot a snake, shoot it with a regular round...the distance snake loads MIGHT be effective is close enough that hitting one with a bullet shouldnt be hard...talking 10ft or less i bet..so id just say carry it loaded with bullets...then if you ever need it for true self defense, you arent shooting a criminal with snake loads on accident..
a compact 40 can be a handful...even for expirienced shooters...then again, compact handguns period are more difficult to shoot than a larger one...but a smaller one carries better than a larger one...gotta figure out what you like and that sorta deal...
if i were looking at a standard sized revolver (not a snub nose) id go 357mag no question about it...you can still shoot 38s to practice..and can shoot 38+Ps no problem if recoil of the mag is too much...
bigger/more powerful rounds are nice...BUT a big bullet that misses its target is useless...a small bullet put where it needs to be is going to be more effective than a big bullet that missed...
hammerless guns can only be shot double action. that typically means a long, heavy trigger pull. a gun with a hammer can be ****ed back before shooting turning it to single action...short trigger pull...single action is easier for most people to shoot as your not pulling the heavy trigger that long distance....im a little different than alot...my double action 1st round from my sig is where it needs to be...but, ive trained alot to be able to do that...(my sig is a semi auto pistol with a hammer that is double action on the first shot then the rest are single action as the hammer is ****ed when the gun is fired)
alot of things to consider and think about...i dont know how you plan to carry it...i dont know when you'll carry it etc etc...and dont know much about snake loads to actually help...but i cant imagine them being effective very far off...and even if they are, i just dont have a reason to kill a snake wether its under my boot or 50yds away...thats just me..