best option is to get a imported 3sge, and freshen it up with new seals and what not, and pop that in, new motor should cost you about 1300-1400 with wiring and ECU, the guy you need to wire it is name jonathan, he lives here in brisbane(cost 400, ~450 for the gold coast that were he did matty's). exhaust wise well that can cost you up to a grand depending where you go and what you want. engine conversions are not cheap, but you will get alot more power out of a 3sge then you did in the 3sfe, note you also don't need to get a mod plate under the queensland road athorities the St162 was released with a 3sge as an option but you have a 3sfe which mean you have and ST, not an SX unless someone has done an conversion to it, confirm this buy the drum only rear brakes.