I may be mistaken but I don't think the one up was upgradeable (options wise).

Its either the the One Up with 100mm x 100mmx 125mm build area (about 4"x4"x5") or the Two UP with 175mm x 175mm x 125mm (about 6 7/8"x 6 7/8"x 5"). This is based on there Kickstarter description.

and neither have a heat bed at the moment. There stretch goal for 750K will add one but right now there is no heat bed. You can certain add one using parts from there site though