Thanks to all for your valuable comments (and time). To be honest, I doubt I'll go for a fire breathing monster (the wife's more than enough of that ). I was gonna go for a diesel originally, so I'll probably stick with a bog standard V8. Despite the "engine bun fight" going on, the old V8 was/is a reliable old lump and parts for it are cheap and easy to find (unlike the wife). I don't even want to discuss knocking big ends. Ooops, too far.
Thanks again. Now to the classifieds to have a good nosey around at what's available.