Jerry,
I found one of the easiest to use GPS for skydiving was the old Magellan XL with a yolk mount. The display has nice large numbers and most functions can be activated with only one or two button sequences. Problem with them though, is that they are hungry on AA batteries (3hrs max) and tend to drop their bundle if you have a stop drop and try and do a quickie go around and re-align yourself onto the same run in track. Can also take a while to re-acquire once the position has been lost.
Most jump planes I have come accross have the Garmin 100 panel mount which is also a good unit but can take a bit of getting used to. Especailly to programme in waypoints.
I couldn't agree more with Gravox's advice!
Hey Gravox, RAIM on a jumpship GPS? I was normally flat out getting the DZ operators to maintain minimum instrumentation on their aircraft much less providing a TSOd GPS. <img src="rolleyes.gif" border="0">
Go for it Jerry, good way to acquire the first few hundred hours but if you hold a CPL or even PPL for that matter, you should be standing your ground and demanding some remuneration.