First, Remede's site has a greate amount of information on all the
PDAs. http://cumulus-soaring.com/pda.htm

I might be a contrarian but .... you might want to stick with your
monochrome display. There is no more readable display, except
possibly the very latest color technologies.

The Compaq Aero 15xx monochrome series is very popular. Even though
this PDA is very slow by today's standards, most of the available
soaring software uses it. You can regularly find them on eBay.

Giving up color has its disadvantages if you want all the maps, gee-
gaws, etc, that the newest software has. For me, I turn off most of
that and go for the simpler-is-better-and-safer mode of flight.

Good luck, John