Bought my Float 30 this spring from a ski shop in California for an awesome deal. They had already test fired the cylinder prior to shipping it (I did not know this at the time). Checked with a number of BCA dealers in town, but no one was was set up to fill the cylinders. The local sports store that does paintball stuff wasn't sure if they were set up or not.
The only ones in town that had a clue was the local Yamaha dealer (Also a BCA dealer) but they weren't going to have the equipment to do so until this fall. I ended getting it filled at the skidoo dealer in another town (Another BCA Ddealer), who also had a dive shop and had refilled them before.
Luckily he had filled them before, and had the proper nozzle the fill the cylinder. The first time he went to fill the cylinder, it would not fill. There is a small o-ring in the deploy valve that can get pushed out of its grove and/or torn when the bag is deployed. The bag supposed to come with a spare o-ring and special o-ring lube from the factory, but mine did not. Luckily the shop had replacent o-rings. It cost me $20 to have it refilled, which I thought was kinda steep but I was able to do a test deploy of my own to make sure it worked.
BCA was supposed to get a network of established dealers set up to fill the cylinders, otherwise you can send it to them. Also SnowBigDeal here on the forum is a dealer for avalanche equipment and has an exchange service for the cylinders as well.
Good luck, and let's make sure we don't have to use our bags!