The way the dollar is, I'd just stay local. Cant go wrong with the 3 big names, Allfast, Dominator or Sling Shot. Get it built to suit your purpose, not something off the shelf designed to stall at a certain speed as it may behave completely different behind your combo.
Just recently had to rebuild mine, its an Allfast...was happy with the original (it was a 4500 behind an LS1) and still very happy with the replacement.