It'd probably be cheaper to get an 8700c housing from a site like Cellular Accessories - SonyEricsson, NEC, Motorola, Nokia, Panasonic, Sanyo and Samsung. Quality housing, keypads, LCD screens, chargers, batteries, data cables, parts.
If you do get one, once it's unlocked it will function just like youer 8700r does now. See the sponsors section for some unlocking services.