Save up for the turbo upgrade! As many others have already mentioned sort out the chassis first. Wheels, stance, handling, brakes etc. You can also start to upgrade other parts in preparation for the upgrade.
I had a pretty much stock NA a while back - MODS = Stainless manifold, 2.5" centre section into a 3" system (fully decatted with one silencer), BC Racing coilovers, wheels, brake upgrade (discs, pads, fluid and braided lines). Everything else was cosmetic - LED dash upgrade, steering wheel, gear knob, smoked indicators etc.
I never had the money to even think about pulling the trigger on going turbo but it was super fun to drive and made me smile.