I also have been in the tripod and head search the past few weeks, and just finally made the purchase. I ended up buying a set of the new Feisol 3 section carbon fiber legs (w/ just a mounting plate - no center column for better stability) for $170 and a Kirk BH-3 for $255.
The three main ballheads I looked at were all universally recommended as excellent, and stood out from the crowd.
Markins M10 - Seems to be the nicest of the bunch, almost as good as the Arca Swiss B1. However, it was over $300, so that scratched it off my list.
Acratech Ultimate Ballhead - at $270-290 new it was a little above my price range. There is a guy on Ebay who sells factory seconds (fully functional and warranteed, minor cosmetic defect). These typically go for $240-250, and there's usually one per week. The downside with the Acratech is that the design is a little unique and some people did not like having to use the panning base to reorient the ballhead to access certain positions. Otherwise it's a great ballhead and well liked.
The Kirk BH-3 is also highly recommended, and is just a couple ounces heavier than the other two heads. The reason I chose the Kirk was primarily because it was the cheapest price (new) and it also came with a free generic plate. Since the plates can cost $40-50, this is a significant savings.
I'd recommend stretching to the upper half of your budget and trying either the Kirk or Acratech ballheads.