Cool do you carry more than one brand or 5.1 fluid ? And are any of them "paint safe" ?
We just carry the Motul. It's quality stuff and always in stock.
There are other quality fluids in the DOT4 category, which is good enough for a street car flush. For street cars / auto-x the key is just to keep dry fluid in the car. For track cars, you should be bleeding and removing caliper local fluid after every track event ... especially if you find yourself boiling it over. We recommend going to a Motul 5.1 and using titanium backers for the pads, but the best solution is venting the brakes with a good flow of air and trying to be aware of how hard you are using them on the track.