RE: esc size
Hi Rye,
If you can't find a (afforable) ESC rated 100A with reverse (and watercooling) you might consider getting one for each motor and use a Y cable to get the signal to them.
35 -50 A should be sufficient, watercooling is always a good idea.
I have to agree with Tony Fitzpatrick on your powersource, that battery will suffer; getting out of the hole, a 700BB can easily draw 35A ( x 2=70A ), once on the plane the ampdraw will be 15-20 A per motor, making a power consumption of close to 500W continuously, that's five times what your battery can deliver...
Two 12 cell packs of Sanyo 2400 RC (one per motor) would be a more battery friendly solution (or Lipo's ofcourse)
Regards, Jan.