Actually, with all this talk of Alfas and Toyotas/Lotuses...Loti...English sports cars, the other options seem to have been forgotten... because you could use a Ferrari engine and box - LB have just shipped out such a beast, built using a Mondial as a donor. Not even remotely cheap, but it made around 308bhp on the dyno, not bad for an old 2-valve V8 motor! Or what about a proper Dino engine? There was one on Ebay recently at about £30K.

Alternatively, if you're of an engineeringy bent, you could just use whatever power unit takes your fancy, so long as it'd fit in. You'd have to do a fair bit of measuring and fabricating of mountings, plus sort an exhaust, ECU, etc etc etc. but it can be done!

As regards my own choice, I was originally going for a bog-standard Alfa 156 donor (2.5-litre, 195bhp). It makes for a nicely-balanced car, enough power to make it quick but not fast, but with thoughts of it being upgradeable to a 3.2 at a later date. That all changed when a few things came together by some sort of fluke and I realised I could afford to spend quite a bit more, so it got upgraded to the Toyota 2GR-FE option and again, I dropped on an ex-Lotus NOS motor still sitting on its engine stand. I'm not bothered about screaming, sky-high revs on the road in a car - I've got bikes for that. So the thought of a torquey supercharged 3.5-litre works for me! Each to their own, though - there's no right or wrong decision here. I'm not in the "must be an Italian engine" camp as the vast majority of the car's British, so as long as it's not an air-cooled VW lump I don't care

I think the best thing you can do to glean info is look around this forum and see what people are doing/have done, and also contact both Hawk and LB for the latest prices and lead times, and then it's down to what works for you. Doesn't mean you can't ask questions here, though, but it's a good place to start. Good luck and have fun!