Regarding GPS systems.
After owning several garmin devices, like the zumo 550 and the 660 i have got rid of them and started using my Iphone 4s instead.
That leaves me with one unit only for navi, comunication and music listening.
With the Navigon software i also have the ability to plot exactly the road i would like to drive. i plot the route in my ipad (or even in mapsource/itnconverter, requires jailbreak) and send the link to open on iphone by mail. it can then be stored on the iphone.
i have been doing several 14day trips trough europe plotting my ride this way.
Here's what i use to mount this on my bike:
Iphone mounted in a lifeproof case with lifeproof mount compatible with gopro mounts.
Some leftover gopro mounts.
12v marine outlet .
Pictures of innstallation:
I have a scala rider G4 mounted in my helmet for voice guide&music etc.
To use the iphone with gloves u need a few stitches with some special thread, called kapasitiv(Nooorwegian) thread.
I got it at IKEA warehouse
Looks like this: