1) If I could have a new 50cal inline now, I'd want the T/C Triumph. But it's hard to ask for more performance when I've got an Omega
2) In all reality, there's no advantage to stainless. Might look better depending on the rifle, might fight corrosion better. But you're going to be keeping your rifle clean and out of salt water (more than likely ). Blued is more affordable and performs just as well in the accuracy department.
3) Keep an eye open for sales at the usual retailers (Cabela's, scheels...), look into Natchez or Midsouth shooters supply.

Be sure the rifle you're planning on purchasing will suit the laws for the state(s) it's going to be used in.