Update: After letting this poll go for about 10 days, I'd say the interest in this idea is limited, heh.
We've had more ppl voting for things like what they put on Macaroni and than this one.
Doesn't mean it won't happen ... I actually think it will.
Meanwhile, the concept would involve maps that don't involve custom monsters. I might mess around with building the required server-side components that meet the requirements for a solid/stable public server.
The maps that could reasonably (maybe) meet the requirement that might be interesting to try the concept on ... and this is just me thinking aloud ...
Some spaceous maps meeting the criteria:
sm82: Rubicondom
trincasp2: Forgotten Tomb
cmc: Cheyenne Mountain Complex
could: And All that Could Have Been
ac: Adamatine Cruelty
terra: Terra Thing
marine: Ultramarine
sm36 : Subterranean Siege
Would need checked for coop spawn points, if not extra coord spots would need to be identified. Plus, would need to put weapon-stay on somehow and maybe have ammo boxes respawn and team damage off.
Probably at least a fair amount of work on the QuakeC side, if not a substantial amount.