try www.mapalad.org to know more about Palm PDAs.
Now as to your inquiry about qwerty keyboard on PDA it depends, so far treo and HP iPaqs is doing it right in terms of form factor. Most people claim that they can type faster, however the downside is you use 2 thumbs. Nokia communicator type of layout is kinda bulky and it may be bigger than the iPaq or treo but the layout made it diffucult to input fast.

*docgorio, most people claim that treo is better than iPaq because of the ease of use and more stable, and i agree with you. however there are times na naghahung ang Palm, i'm not sure with windows mobile so no comment there. But a lot of people prefer palm talaga because of its easier to use and great after sales support din.