Compression ratio of 9.5:1 is a problem, the 91-94 engines ran at 9.0:1
The stock NASP engine can be tuned to around 200bhp safely but to go over that you need to spend quite a bit of money. Lowering the compression ratio and increasing the fuel delivery are the two main issues you have.
Timing alterations, are also tricky, you will probably be better off going for a replacement ECU.
The 300zx rb20det twin turbo engine would make a good donor for an engine swap, this will net a large power gain and ensure reliability.