Not a huge update, but I made up an arbor to do my squish machining when that time comes. I have yet to put an indicator on it to see if the plug holes are centered, as I've read that sometimes they aren't. I also still have to take a light mill cut off of the spark plug surface to make sure that it is true with the gasket surface before doing any machining.
I used a buddy's lathe to make the arbor. He is tooled up a bit better than I am at the moment, plus his lathe has a dro, which makes everything easier.
I'll use my South Bend 9 when the time comes.
Didn't think about clearance of the bed, but I have a half inch, which is about a mile in machinist terms, so it's all good.