Welcome aboard. I heartily recommend the PM25.
It will clear your 8' ceiling. I have mine on a work bench 38" off the floor, and it tops out about 78".
I'm pleased with my mill, sure I'd like quill and X feed, but the alternative to me was no machine. I opted for DRO on X and Y, the head has a DRO on the quill. I've found that I use the column movement to get the tool near where I want it to be, then use the quill for fine control.
I have to clamp the head before using the quill, the head moves .007 in X and .0015 in Y when I clamp it. I could probably adjust that out with the column gib, but haven't yet.
Belt changes, yes, there's high and low. low goes from 50 to 1250, high from 100 to 2500. Matt suggested the machine would live longer if you didn't use the higher end of either speed. In other words, if you want 1250, use high, mid range.
The ways are ground, in comparison to many which are just milled. IMHO the tolerances are as good as commercial industrial machinery.
The DC motor (and its control) and the belt drive are real pluses on these machines.