They are PG4000 (similar to PG4001ML) from Photographer's Warehouse. I'm sure they are not the very best, but the guy who had them before did a lot of nice work with them and I think that just about any equipment is more than I'm able to put to good use right now.
Spent last evening reading a lot on Strobist, so will start playing with the stuff this week... just a single light for starters.