I think I've found the head unit for me
It's the alpine W404r
http://www.caraudiodirect.co.uk/alpine-ixa-w404r.html

I'll be putting this into my facelift vectra but I'd like it to look flush and hopefully still be able to use my steering wheel controls.... do I need any of the following? if so what do I need and where can I get them from?

Steering Wheel control harness?
Fascia?
Cage?