gt2871r vs gt2876r

Hey Guys:

Im in the market for a new turbo for my sr20 red top. Ive had the stock turbo on there, then the gt28r, now im agian looking for somthing bigger. I see alot of ppl are going with the gt2871r turbo with the .64 for quick spool. I was wondering if anyone new the difference between the 2871r and the 2876r, or if anyone had some input which one is the better of the two. Most of the 2871r’s I find do not come with the acctuator. Does anyone know where I can pick one up from.