The car looks super clean - any more pics?
If you love the car and can live with it being less-than-brisk then do that. Maintain it and treat it well, just don't expect to get anything out of it if you modify it.
When you're ready, either swap the donk for a turbo RB25 or just save some money and sell it for a GTT.
I think a lot of people in this topic (myself included) have either themselves wasted a crap load of money on cars that shouldn't have been modified ( ✋) or have witnessed others making that mistake.
Good luck!