Rik if they are comp cams you will need to be aware they will not probably just go straight in as timing with Comp cams VERY iffy, That was what caused me all that trouble years ago I need up putting in saab b207 verniers, you could also look at removing the lug on the z22se verniers, FLD did that. Then you will need to time them properly.
I might be getting the DTA up and running as the Z20let ecu seems to be going nowhere.
your setup is good, think you might need the 2.9 pulley for over 300bhp, chrisuk got 300+ with a 2.5 exhaust system, so 3" might not be needed