There are many options for the launch vehicles. mission sizes, vehicle availability, and orbital assembly options all vary the launch vehicle requirements.
One set of useful vehicles is the Ascent Roadmap
Notes by ...: I have not noted any dimensions for the payloads to be sent to the Moon. Particularly the manned missions. Since this is dependent on the choice of launch vehicle, can anyone advise about where that is going. Do we have a choice yet or are their recommendations available?
In an earlier posting I suggested a two metric tonne PAYLOAD for a manned lunar vehicle. Propulsion and other mass would naturally make it heavier. As a minimum, I was conceptualising a two meter diameter for the manned capsule - but that was for a single astronaut mission, which does not apply here.
A spacecraft for a five-person crew would be at least as large as an Apollo Command Module. Five metric tonnes mass. Maybe less if you shave on margins. This suggests a strategy of staggering crew arrivals by 30 or 60 days and having your crews arrive two at a time. This would enable a much smaller craft delivering two crewmembers each. Almost certainly this could be done for four metric tonnes mass or less for the manned payload.
Working from that criteria set, I get: 3.75 metric tonnes capsule mass, 2.35 meter base diameter biconic, dual-hulled, structure with one hatch, two windows and a launch escape system based on pushing, not pulling, the manned vehicle away from an exploding launcher. The launch vehicle could be as small as two meters diameter - this requiring a hammerhead payload mounting ring structure.
The crew had better not be claustrophobic. The crew could fly safely, but there are no real margins for comfort provision during flight.