Other possible (but more expensive) donor cars?

I think you're right jnjb, any of those options are possible.

Other things to consider are 4 wheel drive versions of standard salloons/hatchbacks, ones that come to mind are the VW Golf, Peugeot 405 and the rare Mondeo 4x4.

You could find a way to use the four wheel drive system, which would be interesting or just use the rear axle with a engine and RWD gearbox.

Cheers

Chris