my best mate is into his vauxhalls and you may say that it seems a cost effective solution, its no different to putting a zetec lump in on a budget. Regardless you want more power and to run more power on the c20let you are still going to need uprated rods, maybe pistons as they are good for around 350 horse (maybe not) loom conversion, management etc etc.
You mentioned you liked fords then why not stick with them completely, I do think the idea of a 6 speed box is awesome though and having been in my mates corsa I can see the attraction.
I say either corsa, vaux powered or escort ford power... just keep it the way nature intended just my 20 pence worth mate