I'm in the same boat mate. I looked into either the 4AGE or the 2TGEU and I've decided to go with the 2TG for the time being. Coz its simpler conversion. The price for the 86kw 4AGE was $4000, and $4500 for the 100kw version. As for the power of the 2TGEU its also 86kw. From what I know yes it can be supercharged, using the same supercharger from the 4A series. This is actually what i am hoping to do in the near future if I get the 2TGEU put in. I'm not sure on the performance after the S/C is put on, but I'd be keen to know. Plus whether u can Turbo it easy,)cheaply aswell.
Cheers