Diane,
Backdrop Express and Backdrop Outlet (www.backdropoutlet.com) both carry some decent, inexpensive basic backdrops. I've also purchased muslin at JoAnne's and painted the backdrop myself using spray cans. Alternately, I've found great fabrics in the discount bins at JoAnne's, Michaels and even Walmart.

As for lights, my AB400s give me F8 @ 10 feet and ISO 200 using silver reflectors or the Alien Bee silver 64-inch PLMs. I'm at F6.3 with a single PLM. And, for me, everything is portable in two relatively lightweight cases including the backdrop stand and light stands. A little extra lugging comes into play when I bring the Vagabond but sometimes that's necessary.

Good luck with the search. That can be fun, too.

Jim