If you know of a cheap supplier....I'm sure many would love to know.

They can be good value, but certainly not cheap anymore.

A lot will depend what you want. Most modern V8's will be hard to find with a manual box already bolted on.

BMW is one option, they do a manual, but it is hard to find.

Audi's V8 range apparently bolts up to some rwd Volvo boxes

Lexus LS400 is a superb engine, it is cheap, but you'll have to sort your on gearbox. I'm sure some people do bellhousings for them though

LSx range. Manuals are easy, but the engines are expensive now.

Rover....not really that cheap these days, and a mediocre performer in anything other than a very light car. But rwd boxes are fairly easy to sort.