Whats the rest of the combo? How much boost are you running?
The stock turbo is hard to beat with supporting mods up to around 22psi of boost. To answer your question:
TA49 and TE44 are the most popular and a Precision 5831 is supposed to be the "new" TE44 which I just stepped up to but it REALLY likes at least 26psi on my stock long block.
My engine and injectors are stock. Both with a fresh rebuild. I can run 20psi. I just have bad turbo lag and was thinking a better turbo would help with the larger down pipe. Another question, most of the time the car starts hard, hot or cold makes no difference and when she fires lots of smoke comes out the pipes. I am almost sure this is unburned fuel. Could I be having a cam senser issue? Car runs fine otherwise.