There are plenty of ways to make up a cheap turbo system. Knowing what you're doing is the hardest part of it.

To get up to 150-175 hp you would need to tear apart the engine and completely rebuild it with new pistons, probably new rods to accomidate higher rpms, ported head, along with stiffer valve springs, new camshafts, header, new exhaust and more. All those parts are going to need to be custom made too.

If you went with a turbo, all you need custom made is an exhaust manifold (modify the stock one for cheap) and the rest of the exhaust. Pretty much everything else you can bolt in and make fit with purchased parts.