Well, there is a whole lot of things to get done when doing a swap like that. Cooling is a major deal, however, the engine management, upgrading the trans, braking, ect. not to mention the cost involved. That being said, the reliability and power you can achieve from an aircooled engine is still better bang for the buck. With a small investment of about 3k, you could build or buy an engine that is very reliable and with sufficient power. My engine which is a 1904cc puts out 85whp and 101fpt. I have a set of new heads coming that should bump up the power to nearly 115 - 120 at the wheels. Not bad for a car that only weighs in at around 1670lbs. I drive it 3 to 4 times a week to work which is around a 70 mile round trip (spring and summer as I live in Wisconsin). Routine maint. on the engine is all I really do. Now, mind you, this set up is not stock by any means. I have dual 44 webers, the new heads will be ported and polished. 1.25:1 ratio rockers, full flowed oil system, merged header, yadda, yadda. The point being, I will spend far less on this type of setup than converting to a Subaru engine. You could even add a turbo setup to the acvw engine and still have it cost way less than a conversion. However, if you are still interested in this setup, check this site out
TSR Dragracers