For all normal operations not involving any EVA activity, the Clark (ACES) suit the Shuttle people wear would suffice.

For EVAs and lunar operations, they're going to have to buckle down and develop a true 8 psi suit. The kind of routine operations that are going to have to be done in space requires getting past all this "prebreathing" crap. If you have to wait hours before you can leave your vehicle, some emergency is going to kill you eventually.

The Ames "hard suit" was the best option I ever saw, and it was stupid for NASA to dump it.

I see no reason that most of the crew couldn't sit in their seats in their ACES suits while the EVA guys went out in the real suits. Not my fault NASA didn't see fit to add an air lock.

I see no reason the EVA and Moon suit couldn't be the same suit, although the Moon suit might want to have a dust and damage cloth coverall.