Money no object,PTC,Ultimate,or Chance would likely be my top three choices.
So between ******* & PTC it's pretty obvious where I'd stand,the guys @ PTC just have way more converter building experience behind them than most of "newer" converter building outfits like ******* and such have,and that ample experience tends to lead to an excellent end product.
But I also totally agree with what Streetracer09 says about ******* having an OK rep with many "milder" combos,so they can be an option as well,especially when the budget absolutely dictates the utmost in restraint,while still hoping for decent value and performance results.
But IMO,with the turbo combo,PTC will be more likely hit the mark.
So that alone might be worth spending a few $$$ more.
2¢
Bret P.