Model12Win,
I have read a lot of positive stuff about the .357 Coonan. It definitely would deserve consideration.
The .460 Rowland/ A 260 grain bullet at 1100+ FPS out of a 5" 1911A1-type gun would be pretty darn good medicine:
http://www.realguns.com/loads/460Rowland.htm
Here's more info:
http://460rowland.com/
Maybe next year I'll work on buying a suitable gun that can be converted to a .460 Rowland.