I agree with your decision to not use JGY. I don't know of any other shops in the VA area that specialize in the SR20. I do have a Blue Bird swapped sentra with the GTiR T28. It makes 260-300whp depending on boost levels. It runs just like my stock sentra did and has for the past 5 yrs. No constant tuning is necessary once you get everything lined out. The car has run 7.8 @ 91mph in the 1/8 on 18lbs with slicks and 12.9 on street tires @ 111mph in the 1/4 on less boost.Realistically you don't need the GTiR motor. It is a bit more complicated to tune and more expensive than the other options. Get a u12/u13 or avenir motor. Try
http://www.tigerjapanese.com, best prices I have seen by a long shot. My car makes the same power the GTiR is capable of by just using the turbo from a GTiR, s15(444cc inj) and z32 MAF with proper engine managment.