I'll vouch for the Raritan PH II's. I put two on board four years ago
and haven't had a single problem. One PM rebuild on each, probably
didn't even need that. Need to lube the wet/dry flush selector every
4-6 months or so, when it starts squeaking, but that's a 5 minute job.
Peggie recommends lubing the main cylinder annually or so, but on this
toilet, you may as well just rebuild it by the time you take all that
apart.

One other item.. be sure the outlet is aft of the intake!