Originally Posted by
Ametz
And since i have a battery at my water bottle place i cant use anything like this

You could always add a 2nd bottle cage holder, and use the GPS you linked to. It would give you the added benefit of having a bottle cage too. There are various designs out there, see Klickfix BOTTLEfix for example:
http://www.klickfix.com/index.php?lang=en
Sorry for the lack of direct link, their site makes direct linking difficult. Just use their product search for BOTTLEfix. I see the new version comes with a fancy QR feature that is probably not ideal in this case, but the older version has no QR.
--J
[edit] monkeying around with links [/edit]