If you can get a decent Fez ST for your budget then go for that everyday!

You could get a fully loaded, reasonable mileage ST170 for 2k but they have LOADS of common and expensive faults, are terrible on fuel economy and aren't much faster (in the real world) than the boggo 2.0 litre

I haven't owned a Fez ST but I have driven a few and, while they aren't THAT amazing out of the box, they are pretty entertaining and you have plenty of options to improve them power and handling wise - you can't get anything more out of the ST170 unless you want to go mad with ITB's or forced induction and most don't make the power they should as standard to begin with.

That said, the ST170 is pretty well screwed together and will be much more refined and comfortable over your time with it, but it will be an expensive trip and won't set your world on fire.