Ideally you would want 900-1000mm clear space in front of your vanity and for walkways, unfortunately we don't live in an ideal world and have to work with what we have. 700mm would be the absolute minimum width for a walkway to still allow reasonable passage, although I would be reluctant to go this tight. A floating vanity will help the space look larger and storage can be included in a mirrored shaving cabinet or mirror with shallow shelf above the vanity.

Thanks for response, great website I can see myself wanting to spend too much time on there :) I'm thinking of having a crack myself now as brother in law has a drop saw and said he can give me a hand. If it's a total disaster then I might look to a site like that but probably can't afford it. I was thinking a carpenter could knock it up quickly from scraps rather than an artisan but perhaps too specialised.

Invest in a custom made one from your local glass and glazing specialists - it'll be made to fit the vanity top exactly and the edges of the mirror should also be sealed to prevent corrosion. (which often happens to mirrors from the hardware stores)

Approach any local cabinet maker. or an online kit supplier that uses polytec