im not recommending a minimum of .44mag because the .41mag is definatly got enough power, but i do recommened the .44mag over it because of ammo availabilty unless you reload.
I think ruger offers the best options, though taurus and S&W offer some as well. Whether you like DA, or SA is simply up to the way they fit your hand. If you like DA, a redhawk or super redhawk in .44mag is a good choice, If you want SA a blackhawk of super blackhawk is your gun, in .44mag if you dont reload, or add the choices of .41mag and the .45colt if you reload. i recommed the 6.5" to 7.5" barrels as my favorite but again this is extremly personaly preferance
if you think you might want to mount a scope, get a Ruger super blackhawk Hunter model as it comes with a heavier barrel and intergrated scope rings

propmahn
save the world, reload your brass