I have a 1990 NA 2+2. It was a barn find. Engine cranked but didn’t turn over. A good majority of the wires on the EFI harness were melted (the reason it sat) due to a coolant hose exploding. The frame and body were rust free. Of course the paint wasn’t great but i scooped it up for $1200. I’m tearing the whole car apart Becuase it sat in a barn. (Mouse poop and nests everywhere). For my options on an engine I was thinking about rebuilding the NA engine and then building a TT on the side after the NA is done and in. Or I could convert the NA to a TT. I’m not too worried about the cost of either. Looking more for the convenience factor of it.

any personal opinion would help

Have you explored an LS conversion?

Z1 Motorsports has an N/A to TT conversion document. It's not just adding turbos. In fact, they recommend a whole front TT clip.

Here's a great thread: na-to-tt-conversion-not-your-normal-conv-t506819.html

If money is no object my recommendation is to buy one of the fully built engines and aftermarket piping sets. Parts alone for annendevaour of that sort you're looking at 12k+