I have both PalmOS and PPC. If you are only interested in the PIMs: schedule, contacts, task, I would go with the Palm Zire. Small, light weight, the rechargable battery last forever between charges. Yes, it has small memory and no backlight but 2MB is more than enough for PIMs.
But, if you want to do more, I would recommend getting a color unit, either OS. One thing I would look at is your other electronics and the memory cards they use. Do you have a camera or other electronics that uses compact flash, sd, or memory stick? I would try to stick with one or two different memory formats.
Go to a best buy, circuit city, compusa, etc and play around with what they have. My personal recommendation would be a Dell Axim Basic. It uses both CF and SD, great battery life (better than other PPC's and most every PalmOS unit), and is usually between $225 and $175, depending what special Dell is running. Much more powerful than Palm units in that price range and better than most PPC's costing more. The only drawback is that it is a bit bigger and heavier than many Palm units.
Hope this helps
