You'd be better served posting on some dedicated scooter forums based in the UK to be honest, but...
A couple of scooters that I've heard are pretty good (assuming that he's 17 or over and can do the one day CBT course), are the Honda PCX and the SH125i, both of which are 125cc scooters. The PCX will likely look better to him but it'll be a little on the small side if he's 6 foot or more. The SH125i is actually slightly more competent but has the more tradition styling.
Have a look on the Honda site here for the specs, pictures and more detailed info :
http://www.honda.co.uk/motorcycles/scooters/
I'd also recommend not buying anything blind. Take him to a decent motorbike/scooter place to look at them. Ask a load of questions in there and take their comments on board. Don't forget that someone will have to pay for the CBT, a helmet and other gear, a lock and chain maybe, the insurance and road tax too.