I would get a new intercooler and downpipe, since you already have an intake and exhaust. You basic mods to get more airflow and better performance. If you are planning on upgrading your turbo, just use the stock dp until you get the new turbo and downpipe, in case it isn't the same bellmouth housing. Here is a link to the piping EMS has:
MR2 Sidemount Intercooler Piping - $199.99 : EMSPowered, High Quality, Great Service, Low Prices. If you are going to upgrade the intercooler, just get the pipes at the same time.
Other mods could include some TRD parts...those are always nice! haha.