Since you're using a medium-format negative and grain isn't a significant concern, of the last two recommended, I'd start with APX 100. It's a much easier film to handle than TMX, and produces simply gorgeous results - much nicer to my eye than TMX. A well-exposed 6x6 APX 100 negative developed in nearly anything (except, say, Rodinal) should blow up pretty darn big before grain becomes an issue.(posted 8933 days ago)And in my Minox-negative-blowup experience with ALL of the 100- and 125-speed films in the last five years (all dev'd in D-76 1:1, with some rolls in XTOL 1:1 or Microdol-X 1:3), APX 100 was consistently right behind TMX and Delta 100 in the high resolution/sharpness and fine-grain category (and quite clearly in front of Plus-X and FP4 Plus). It's a wonderful film, and with an old Rolleiflex, a match made in heaven!
Nothing against TMX - I use that a lot too, but there's no getting around its more temperamental personality. However, for medium format, I'd definitely go with APX 100.