Rob (from SkyDemon) here, and I can say that RAM mount is definitely worth checking into. We use their solutions for building our expo "iPad tree", and they have an incredible array of mounting options... their sales guys are pretty good at helping you narrow down exactly what you need too.
With regards to GPS its worth noting that since various developments that we have undergone, we can now take position data from certain wifi based sources (as well as the classic Bluetooth method) such as collision avoidance tech, or the Dynon Skyview. I think that as cockpit hardware becomes more wireless we will start to see a lot less Bluetooth GPS devices being sold, since GPS by wifi output will come as standard with modern hardware.