sr20 build words of wisdom??

[SHIFT_*grind*]

You might try to find a better manifold than an SS Autochrome. They're common but still not the greatest build quality; you might end up replacing it, or repairing it, sooner than you think. Decent manifolds (i.e. not Ebay/SSAC/Megan) are usually pricey, but you could probably look around and find some sort of deal.

I'd advise against an HKS "style" BOV, you can find a BOV from a legit company for a decent price.

You shouldn't need a new oil pan, unless the factory one is dented. Unless you meant a larger aftermarket pan, which is always a good idea for an SR.

Universal O2 sensor, eh, why not get an OEM one? =)

Cross-drilled rotors won't have any benefit for you, unless you'll be tracking the car and heating up the brakes a lot. If it's just a street car, I'd say just go with quality blank rotors.

I'd advise you to spend an extra $150-200 and get KYB AGX shocks. They're adjustable and more suited to sport springs; the GR-2s won't last as long on a lowered car.

Also, Taka turbo lines (or Circuit Sports, or whatever other brand makes braided stainless lines) will make your life a LOT easier if you ever remove/install the turbo, especially if the engine's in the car. You don't want to have to deal with the stock lines.