I don't recall the amiga technologies ones being very different, apart from the branding so it would be worth faking one for that kind of money.
Obvious difference: whole case front
Sure, it might still be worth getting some case fronts molded up, but it's not as easy as just changing a label.
As for the OP's question, I'd tend to lean towards the A1200, especially if you don't get to look at the A4000's board for battery damage first.
edit: yeah, what danwood said, though the case metal was the same (both made by Enlight.)
