Can pick them up cheap on ebay.
The WM5 versions are clunky and a bit tiresome at times. But then the contact list is superb and I like the mobile email/internet/msn etc very handy.
If you want GPS, you can get them with it built in (I do and it's much better than without).
Be wary of the older 200mhz models, as they will NOT run GPS software very well at all. (It'll crash a lot and be very slow). Just get a 400mhz or more. Intel chipsets are better.
I have a bluetooth GPS receiver I'd sell you for a few notes, could also sort you out with Tomtom/Copilot. I personally prefer Copilot.