After much deliberation about various floor covering options, I've gone for some cheaper two part epoxy paint which has been used by two people I know with good feedback.
This is the stuff I've gone for: http://www.morganpolymers.co.uk/products.asp
I also have some concrete sealer, so the plan is:
- Diamond grind the floor
- Vacuum
- Seal (twice)
- Two coats of epoxy
I've decided to do it in white.