need help: how to spend money

so my day job is doing IT for a law firm. they have asked me to compose a book with headshots of every employee (around 250 in our local office.) i think i have enough to get the job done as is: 3 hotshoe flashes with optical triggers, umbrellas and stands, some gels for the background and a gray backdrop, and a couple of reflectors. so that should work for a simple head shot, but they have offered me a budget. i'm not sure how much but i want to give them a high end around $600-$700 and a low end around $300.
now the question is what should i buy. for the low end i was thinking maybe just a skyport set. for the high end a couple of monolights with accessories. what would you suggest and which brands? thanks in advance.

I would...............

Buy one or two more hot shoe flashes with optical slaves so you have front, fill, hair, edge and background. You can fill under the chin with a reflector. $150-$200 and shipping if you get non-dedicated flashes like Sunpak, Vivitar, etc.

Skyports are great. I use and enjoy them. You can buy one trigger/receiver set and trigger the remaining flashes with optical slaves (what I do). $180 and shipping.