Never been that interested in this particular sort of technology personally but....
1) I'd like to get the best there is for the fast approaching crossing of the Torres Strait. .
2) Then keep it for general use once Im hooked (as Im sure I will be)
3) Also suss out the options for stocking it in the shop for others.
Really appreciate some feedback from those who know field to help choose whats worthy & what may not be.
All the stuff Ive seen on posts here would be of interest.
- obviously track logging - Im guessing they all do that but some may do it better?
- time & speed recording - as detailed as possible rather than just averages?
- anything new on the height of jumps would be awesome?
- compatibility with software for dragging out specific stats ?
etc etc.
All info appreciated including brands & sources.

Post or PM - all good
Taa in advance.

I just use a Garmin dakota (wouldnt really mater which model, just get one that can connect to a PC).
As most of these GPS are only water proof to 1m, I also put it in a waterproof pouch just incase a bad crash puts extra pressure on the seals and hang around my neck under wetty or rashy

For your crossing you will want long battery life and large storage
I would also recommend using it before you go and tray out the different settings of the track record, nothing worse than a last minute purchase and you aint got a glue how to use it and it didnt work! (just use in your car for a couple of days)

I am not into the speed so much, those guys use a gt31

As I come from 4wding I use a program called Oziexplorer to download off the gps.
I can upload waypoint, tracks and routes to and from the gps.
Save a track in google earth format to easily share with others.
Forget the height thing it will never work with a normal GPS to be accurate any better than +- 5 or 10m.

You can do all of this with Apps on iphones and android phones now. One App that does it is called Endomondo, it even has a kiteboarding setting! There is a free version too. So no need to buy a dedicated gadget!
Just make sure the phone is tucked away in a good waterproof zip-lock bag... or 2!
Might be good to have the phone for an emergency too.