Now that's a filter wheel, Gary!
I've mainly gone with the OM lenses since I have a few of them from my old OM-1. I don't think focus will be a problem at infinity... during my first play in the obs the other day I had to add a +2 diopter close up lens to achieve focus at about 1.5m with the 50mm lens on close focus setting of about .45m... so stars should come to focus somewhere short of infinity on the lens.
Al.