You can build a h23 better IMO. H22 is 200hp stock with 160 trq. H23 are 160 and 160. Overall, I think powerwise, go with h23. IMO. So basically its up to you. If you like V-TAAAAKK then get a h22, if you like boost, get a h23!
If it overheats, it might be a thermostat or something.. or low on coolant. (burn or leak?) ie headgasket.