Turbo

[Wally]

How handy are you?
Its always a balance between your own capabilities and an already made system (anything other than megasquirt)...

You could do suck through, but that would require even more experience with sidedraft carbs imo. Best to go to someone who has something similar running and ask the details there.
In general EFI rocks but does cost some and even then you must do it all yourself. The rewards are high though. I made 270hp on a basically stock 2 liter type 4
But if all of the above is out of reach for you, you could probaly get more hp from a relatively simple increase in bore (103) and stay N/A. That could get you an easy 175 hp with the right heads and 44 IDF's.
However don't get the misinterpretation that just turboing it give you an easy 200+ hp. 200+ hp is never easy nor cheap. Just more easy to attain with turbo then N/A, but costs about the same... unless you are a reaaaaally good/experienced wrench and use all used parts. Using used parts and tuning it right is however even more difficult and/or time consuming