oh yeah boost the hell out of it!!!! If it was my motor, maybe some new pistons, rings, bearings, and a new headgasket with some valve stem seals and new gaskets all the way around. Maybe a timing belt, water pump. Rebuilt the motor. By the time you get the money for the turbo. Motor will still be full of life. But a compression check and leakdown test will tell if the bottom end is in good shape. If it is great, then the problems lies else where.
Tune it up, check it out. If all is well, then boost it. I have seen stock b18's hit 300whp on stock everything. Its all in the tune. And the condition of the motor. For peace of mind, if your going to boost it, then rebuild it anyway.