Sounds like the OP is not really interested in the Classic. I'm thinking the Classic II and SE/30 are sort of tied for first place. It would come down to desire to expand, aesthetics, ease of repair/maintenance, perceived future value (if that's important). Some people like to just have a basic stock system and/or try to squeeze out performance in a minimal way, while others like to find upgrades/tweaks and max out their machines. If you decide on the Classic II you might want to keep the Classic around for spare parts if it is working. It's probably a little easier to find ADB peripherals which might be important (Mac Plus lacks ADB). The Mac Plus seems to not get as much love in general since it is in the middle of the compact product line-up and one of the most common models.
+1 :b&w: