Maybe more cash than you want to spend and not quite what your are after but a Gefen 1:2 HDTV DVI hub may be ideal for you - and maybe using MemA and MemB will achieve what you require for the differing display devices (we still have MemA and MemB? Gordon)
Yes Joe we still have mema and memb. We also have mema and memb's for different scan rates too (as well as inputs). So there is alot of scope for automating settings with two different resolution devices.