Ask YC: Patent Lawyers who work on equity/fee deferral

So I am somewhat new to patents, but I am working on an awesome fitness startup. We have been testing our equipment and software, and our hardware advisor says its time to file at least for a provisional patent. I am not a fan of stealth mode, but luckily here in the US you can get away with talking to people about what you are doing, and have some testing ( we are currently in a gym already ), but we need to file before we start collecting revenue and go into the appstore. Anyone know/have experience of a good IP law firm out here that works with startups?