Carefully decide which PCB items you might want in the next few months and buy them now - you get an accessory discount of 5% per light ordered so 2 E640s gets you 10% off all accessories ordered (except the mini) With the 60-day return policy it's easy to stock up and try stuff. Note tho you probably won't return anything 
I would get 2x white 64" PLMs with the black backs, one of the square softboxes with grid, the PCB stands, the Cybercommander, trigger (CST) and CSXCV, at least one 8.5 reflector, the grids for the 8.5, one mini per light and PCB bags for everything. You might consider a spare modeling tube, flash bulb and mini battery if you can't get by down one light. You might also consider the lower power modeling bulbs if you want modeling lights when using the minis.
I ordered my PCB stuff 6 weeks ago. 2 E640s, 1 AB800, 2x8.5, grids for 7, large Octa w/ grid, ES 64" PLM with diffuser, CC, 2xCSXSV, CSRB+, two minis, PCB stands, bags for all.
After 2 shoots I returned the AB800 and 7 grids for another E640, CSXSV, 8.5 and grids plus a CST.
The ES 64 with the front diffuser is too specular for my normal use so I'm using Westcot 42" shoot-throughs until I order the 64" white with black back. I wish I'd gotten a smaller softbox but I'll keep the big one for now.
The Mini's already saved by bacon on an indoor shoot when the carefully scouted location had 8 outlets - none of which worked! 400+ shots of various combinations of a family in 45minutes and only 2 misses (both times due to my out-shooting the recycle time - gotta love toddlers)