Put your 350Z engine in there

Seriously though, the 2.0L 16V ABF from the MK3 seems to be the favoured cheap engine which you can pick up on ebay or scrappies. If you're lucky you can get a VR6 lump pretty cheap which may have more power straight off but it's heavier so not favoured as much, but OMFG the sound of a VR6 can not be beat by any of the VAG range of that era.
If you've got about £3k-£5k you can get the 1.8T from many of the VAG range which is very tunable.
2.0 bottom end from a MKIII Gti will be what you want. Engine code of 2E and I think also AGG.
Nick
^ That's also a nice cheap mod
