Scooter for a tall person
Chris the Italians have usually made the Scooters with the tallest seats . But seat height is not the only criterion , you need to have sufficient space for your knees between the seat and the handlebars , as they need to turn lock to lock without being snagged by your knees . I think that most machines to suit you will have larger diameter wheels which gives a longer wheel base .
You will be looking at a seat height of at least 800mm to 840mm . As suggested you will have to try them for size .
To get you started Google the machines I have listed below and then try and find a Dealer that stocks them .
Aprilia Sport City Cube 125 £2820
Aprilia SR Motard 125 £2271
Gilera Runner ST 125 £3271
Piaggio Fly 125 £2371
Honda SH 125 £3099
Kymco City 125 £1799
Kymco People One 125i £2199
Sym HD2 £2699