Brian, I think what your asking is, does the 2210 VW engine compare to the modern 2.2 subaru engine? Maybe I'm reading too much into your wording? But you need to understand that a liquid cooled car has more torque and hp at lower RPM's. This is because of several things but the biggest being the subaru engine has electronic fuel injection. On a subaru, you will generally speaking, have a much lower gear differential or rear end and then have an overdrive. This can be accomplished with the air-cooled engine, but you have to be willing to except some of the routine maintenance and inherit cooling concerns with that type of engine. If you go to the knowledge section you will see some posts from George Brown who posted some great ways to help in the cooling of the aircooled engine.
I would normally give you my large VW displacement speech, but since you know about VW engines, I think its safe to assume you already know about some of the pitfalls in having a large VW engine without proper parts and proper cooling.
Do you like working on the VW engine, and is something your willing to do at this point? If the answer is yes, then continue with your research and then ask for advice and make sure you check with someone about who and what engine will be appropriate for you.
The good news is Jim Ward has a 2210 and lives in Oklahoma so maybe you could setup sometime to go see his IM and get a feel for the power of that engine. I think most people would say this is plenty big enough in a speedster, but it does fall a little short of your stated goal. Keep in mind the hp on the VW engine many times happens in a higher RPM band, but you can get together with a builder to build the power down lower in the RPM band to make it more like a modern engine. Below is a dyno of a 2.5L subaru engine hp torque stock engine.
