[Balloon] IO-board

I bought a balloon board - arm version but not the latest and 2 displays via
wookey. however I have no control board and would like to know what that
costs.
Ive been doing paperwork for a system for it and looking into various things
as Im creating a GUI-desktop, that doesnt load the cpu too much.
Also, should I rather move on to the newer version with a more powerful cpu?
and in that case what does it cost - I need all necessary parts.

regards,

Bjorn Ove.