Looks like this is the basic map:

#1-12
Annual #1
#13-22
Annual #2
#23-29
(Janus Directive, includes #30)
#31-57

With potential option crossovers with Millennium.

I'm looking at my Superman books from the same time period, where I'm averaging 20 issues per book at a comfortable size, so this looks like 3 or 4 volumes.

If I just added all of JD in (including the Firestorm epilogue), then that's 70 total issues. The midpoint split would be around parts 4-5 of JD. If we skip JD, then it's 59 issues, and the midpoint is somewhere around #28 anyway.

So, we might as well split it between #29-30, and make JD it's own book. Besides, I'm a sucker for crossovers. I don't really have interest in most of those titles long term, but I'm fascinated by the crossover.