I've been narrowing down a list of cars that I can afford and can insure now but are very good bases, one of them being a ford sierra sapphire. The plan being as insurance/financial situation permits I can evolve the car.

Before I hunt down a nice solid saph shell, am I right in thinking a stock Sierra Sapphire is the same base as the Sierra Sapphire Cosworth? I could just bolt on Cosworth dampers, springs, roll bars pretty much straight on?

How much do medium millage YB's go for? I've been thinking of taking a zetec up to 200bhp but even with my ghetto tuning after somebody's flowed the head I'm still looking at about £1500 minimum for everything.