There's really no best tube, but I would stick with the 12AX7/ECC83 class tube for units like the MP. I can give you my preference for a brand that I use in most every tube device these days. The JJ/Tesla ECC83-S is absolutely without question my favorite tube for both starved plate and high plate designs. In fact, one of the sweetest sounding tube pres I own is is the PAIA dual tube mic pre Model 9407K that I built and heavily moded from a kit. It's starved plate, but you wouldn't guess that from the silky smooth sound. These come stock with the common cheap Sovtek or Chinese made 12AX7 variants. After a lot of experimentation I settled on the JJ/Tesla ECC83S. It's very true to an old Telefunken design, but much less expensive and every bit as capable. Very impressive. You could pop in a 12au7 and get something interesting I suppose, but personally I wouldn't waste too much time with the others you mentioned. There's enough variety in the character of different 12AX7/ECC83 types to keep you busy for a while experimenting.
"If you canít make a hit record with a Tascam or a Fostex,
then youíre not going to able to do it with a Studer or Otari!" -David Mellor