If I had the money I would go with a duratec, surely there will some focus (2002 >) that has been pranged. They have really good tuning potential.I'veonly done a little bit of reading on them (if you can get hold of a 2.3 then 300+ is achieveable).
This months (or last ?) Practical Performance Car(PPC) Mag has a "how 2" on tuning them. They are really strong, fairly lightweight, rev to 8k standard and 150bhp. That can easily see 200bhp with a few mods (due to ghey restrictive exhaust /emmissions friendly stuff)
HTH. Ill update tonight the specifics when I get in from work and browse the magazine