If you reload your own ammo, the .45 colt can be loaded up for the LARGER frame rugers to give hitting power like the .44 mag. Lots of folks do this but myself, I keep my .45's for fun shooting lower pressure ammo.
Have you considerd a good "Super Black Hawk"? They come only in .44 mag calibre! They come in all these barrel lengths & a 10-1/2" too.
Again if you reload you can tailor your ammo to fire gentle or Hunting type loads.
A good .357 magnum is a great calibre, & it would be a good choice as well depending on what you want to do.
I look at it like this, get the one you like first, then later you can always pick up those others you would like to have. Good luck choosing!