The Ulticontroller board including the display and sd card reader is still available as spare part as it is still used in the UMO+. Get in contact with a larger Ultimaker reseller to get one. There are plenty of designs around for a cover of the Ulticontroller board I think.
The heated chamber cannot replace the heated bed, especially not for materials like PC which need a build plate temperature above 100 degc. The temperature of the bed should match the glass transition temperature of the material (usually slightly above or at least close to it when using additional adhesives like the glue stick).