I mean you could just buy a regular bottomless PF, from LM or elsewhere.

Out of those I'd probably lean you toward the Micra. You don't drink enough to really want to get into a Mini. The faster warm up of the Micra, the smaller footprint, service history of LM, and reduced cost are all in your favor. I don't believe there is a difference in shot quality between the Mini and Micra unless you are pulling commercial quantities. I think the number was 4 shots before a temp change and 7-8 before a taste difference in a row.

It is a bit easier to work on the QM, but to have to mail order parts. Preventative replacement of seals and cleaning can save the surprise need....although even when diligent stuff pops up. My gicar board puked this week, but it was an easy fix.