You forgot to include 222 MHz. With 222 MHz, you would sell a lot to weak signal VHF guys. It is even more lacking in commercial gear than satellite capable rigs.
I loved Mode A, so I second including 28 MHz. Plus if you don't include 222 MHz, people who have transverters can use 28 MHz as an IF.
I assume that you are talking about two radios in a single box, or if not you should be. One of the radios at least should have a separate receive input to facilitate separate feedline runs to a mast mounted preamp. That simplifies switching at the antenna a lot, particualrly with a built in sequencer (by band).
Two antenna inputs per band. This would allow a high gain antenna and an omnidirectional antenna to be used without antenna switching external to the radio. The ability to share a single antenna input between band or bands would be nice.
I rove a lot and would like the rig for that. For roving, 100W per band, perhaps 30W-50W on 902 and 1296 is the minimum acceptable for portable use. If the power is adjustable per band, I do not see the problem with this power level. Also, there is a lot to be gained in tropo work in going from 25W to 100W, lots and lots.
Good front end filtering is essential.
With a SDR, why not build in a computer with tracking, logging, digital modes available. Just plug in a keyboard and mike and go.
IF output is very useful for lots of things.
A pair of K2s, equipped with the XV50 to XV432 series transverters come close to meeting your requirements, as does a K3 equipped with the subreceiver and XV144 to XV432 transverters. In particular, the Elecraft implementation of transverter interface and switching is very nice. - Duffey
-- KK6MC James Duffey Cedar Crest NM