Please help turbocharge my Volvo 1800

[VolvoHeretic]

Greatings all, sorry to butt into your forum, but the Toyota Supra is about the only turbocharged car I can think of that is about the same configuration as my 3 liter 6 cylinder Volvo 1800.

This engine has 2 valve heads w/ solid lifter cam-in-block, 8.7:1 compression, all cast iron and puts out about 138hp w/ 6000 rpm redline.

I know nothing about turbos and wonder if anyone can point me in the right direction of selecting a turbo to get started. I don't have enough room for a twin turbo setup like the late model Volvo's have for this size engine and wonder if the turbos out of a 4-banger will be big enough. I also don't have a lot of money to get started with and hope to find an existing donor car to begin with. Also, 250-300 hp would be fine with me.

Google searches have been awfully tired.

Thanks for any information.