Allotments 4 All

Thanks to everyone for their input. I think I'm moving in the right direction regarding plot preparation. Could anyone now advise me on varieties to plant. I've calculated that my plot can comfortably accomodate 20 crowns so I thought 10 early and 10 later varieties. Connovars Colossal seems to be the patriotic choice but what's the advice from successful allotment growers out there? Thanks in advance.....Chris