Just let me add some information on the Bluetooth connector of the M4 expansion board!
The connector is a JST ZH series (http://www.jst-mfg.com/product/pdf/eng/eZH.pdf), available i.e. at digikey (http://www.digikey.de/product-search/de ... k=JST%20ZH). For the BT connector I have used the 4-pin type, mating connector housing is ZH-4 (supplied with the board; please check the socket! it's plugged in!).
Now, were to get the cables from? Nothing easier than that: use either Spektrum X-Bus cables (SPMA9579, SPMA9580, SPMA9581) or Spektrum satellite cables (SPM9010, SPM9011, SPM9012, SPM90103, SPM9014) to build a cable to your BT-module. The cheapest way to get cables is buying HK spectrum satellite cables (http://www.hobbyking.com/hobbyking/stor ... duct=31437).
I've also added a link to this info the the beginning of the thread!