here my opinion. you are hindered by the automatic trans, thats the only thing stopping you from boosting 7-10psi. The stock MSP manifold, S and J pipe, intercooler piping and turbo are more than enough to destroy the trans. Get a used MSP setup for cheap, put her in, add a tranny cooler and oil cooler if you dont get the MSP one. At 4-5psi the stock system wont be working hard at all, you know it will be reliable, cheaper than aftermarket stuff and capable of boosting 10+psi down the road if you decide to upgrade your tranny internals or swap a 5-speed. Sure aftermarket stuff is nice, but it is not needed until higher boost levels (10+psi) and ya it might make a bit more power at 5psi, but you could just turn up the boost to 6psi and it would be just as dangerous since boost level has nothing to do with what your tranny can take before it blows and under 10psi is easily managed by whatever fuel control you were planing on using in the first place (im assuming rrfpr)