Lego DACTA is the School consortium branch of the Lego company.

They stock some excellent robot building kits- including multiple Lego RCX kits, and Robolab software, as well as specialist stuff like the Lego energy center "eLab" including the Lego Solar Panel.

A number of UK Redistributors are prepared to sell this to hobbyists and small Lego groups. It is also a good way to get bulk sets.