Desktop/Tower with removable hard drives

Because I still use XPpro in both 32 and 64 bit guises on one drive, I want to be able to remove the hard drive and replace it with Vista 32 and 64 bit

I have tried to find a manufacturer the enables the removal/insertion of a hard drive from the front panel (which would need at least 4 bays).

Can anyone guide me to a manufacturer or bespoke assembler that is willing to provide.