I actually have access to a cheap K20A3... I know they aren't ideal, but what can be done to them that's cost effective and will bring the power up to the 200-220 hp mark? Or are they really not worth looking at? Are there items that I can install on a K20a3 that I can reuse later on better base. Things like flashing the ECU to a honda k-pro, cams etc.

I was thinking I could build the car and get it running the the K20A3, whilst I source and build a higher power K20a motor. Given the cost of this build I think I would probably look to get a little more power out of the engine than I was originally planning. I may as well go the whole hog if I'm going to do this. I've already sourced a 6 speed box for the mazda which I'm going to put into it for this year. The 6 speeds can handle mode torque / power so it will be more suitable when I do the engine conversion.