You may want to look at the RY725AI as an alternative to the RY836AI. They are on e-bay for $17.50. I have compared several GPS receiver and these work pretty well for the price. They do not have the bro alt, rate gyros, accelerometers, or mag compass. Stratux does not officially support these right now, and Foreflight may not ever, so right now they are just wasting power.
RY725AI 10Hz UART USB interface GPS Glonass QZSS antenna module flash memory
http://www.ebay.com/itm/RY725AI-10Hz...0AAOSwDk5Tw7TD
If you need a housing here is one that I designed that has the option of using either the RY725AI or RY835AI/RY836AI modules through the use of an adapter.
http://www.thingiverse.com/thing:1378271
- larosta