Stock 4G64 crank, rods and pistons? What compression ratio do you want overall? I know you are looking for advice on what to do but without knowing what end result you are looking for and more about your setup, it's difficult to do that. If you intend running a stock GVR4 or 2G ECU then you will want to try to match the stock 7.8:1 or 8.5:1 CR that those ECUs are tuned for. I can't remember what the 2.4 CR was stock but I am pretty sure it was much higher, I doubt that you can compensate for that with a head gasket.
Maybe that's why you are going for the EVO 8 ECU to give you some tuning options? I personally wouldn't go too aggressive with the CR so I'd be looking to drop it down to about 9.0:1 for the street myself but that probably means new pistons (maybe new rods) if yours are currently stock. If you are going with stock pistons and rods, I'd be very careful if you do have a higher CR. Even the thickest head gasket isn't going to drop it down much and a high CR plus boost requires very good tuning. I'm not saying it can't be done but it must be approached very cautiously.
Get back with more on your setup. Stock or aftermarket pistons and rods, current CR and plans, type of turbo, intercooler etc.