Full size should fit fine. Lots of choice here, including extra protection from gel padding and sheepskin lining for sensitive skin. You could also consider Dalmar boots.
Equestrian Haus has them all ...
Eskadron Tendon Boots
http://www.equestrianhaus.co.uk/index.ph...p;Submit=Search
Dalmar...
Not seen it on ebay but this dobert blue crystal flower browband is lovely - bling with class !!!
http://www.equestrianhaus.co.uk/index.ph...cture_id=9&
How about Dalmar Carbon Fibre Overeach boots? They are very light, easy to use and keep the leg cool when moving.
http://www.equestrianhaus.co.uk/index.ph...acture_id=&
How about some Eskadron White Boots?
They have lots of them on this site, although not always photo in white!
http://www.equestrianhaus.co.uk/index.ph...p;Submit=Search