TCI street fighter is a little cheaper than a PA. Both are rated to 450 fwhp as I am sure you know.
I personally have a street fighter and put down 260 rwhp and 253 rwtq with a few things left to change (better exhaust, ditching the street avenger going to a 4777 with the HP main body).
So I am not by any means knocking on the door of 450 but its held fine.
BUT, there is a guy on ebay out of North Carolina that builds the late model c-4s for next to nothing that has 100% feedback and can build them to your specs and it comes with a converter for around $500. That seems like a heck of a bargain.