200 HP from an SR20 is easy...use N20
Get cold spark plugs...£50ish
N20 system...£500ish
Fuel pump...£200
Take you exhaust system off from the downpipe back, and dial in 5 degrees retard on the ignition timing. Then put some Optimax or better fuel in the tank and run a 100 shot.
You wll clear 200 HP no problem and will have way more han 200 Lbft as well.
200 HP N/A from the SR20DE isn't hard, but can get costly...
You will need the following as an approximation...
S4 or bigger cams - £400
House Filter with intake pipe - £200
Good exhaust at least 2.5" bore (no powerflow shit) - £300
Tubular manifold - £400
Higher compression, i.e. skimmed head or high comp. pistons - £500ish
Head work - £500+
ECU w/ RPM upped - £400+
Fuel system - £300ish
Flywheel - £300
Bolt ons - £300
That's quite a bit for 200 Hp and you will probably surpass it with that setup...
Go with the easy option.
Get a VE motor, use N20 or go Turbo!
Dave