i did a small cars conversion. bell housing short sump etc about $3k in parts. I don't like the clutch set with the bell housing it works just fine but there is a big gap on the bottom as the bell housing mounts the engine. The mechanic who did the job said thats ok, But I have never seen any vehicle with an opening this big. If i was going to do another conversion I think a would consider an adaptor plate and stay with the VW clutch. Another thing that bugs me a little is although the job was done a bit over 2 years ago i have only done 12000 ks and the clutch has started to slip.
Oops sorry its a 03 2.5 Subaru motor. if your going down the subie path i highly recommend the 03 motor its the newest engine before drive by wire. Although these days i don't suppose thats so much of an issue. over all i am very happy with the conversion.
Small cars are a great company to deal with too
Good luck with it.