I have the T5. Does everything I could ask for and then some. Lots of memory, fast, great resolution. I have a ton of programs on it (ePocrates Essentials, PocketEM, PEPID EM & Lab, Stedman's, MedCalc 3000, Washington Manual, and of course, Tetris).
I think it's overkill though. I only have this thing because I'm a geek. You can probably get away with something less pricey, such as the Zire series.
Palm is coming out with a new Tungsten T model. Currently it's the Tungsten xx, but it's anticipated that they will change this to a T6 or something similar. It will have Bluetooth and built-in WiFi (the T5 lacks WiFi, but has built-in Bluetooth). It will have a slower processor and less memory, but will still be ample for nearly all users. The price is about $100 less than the current T5.
Here is the link with info:
http://www.palminfocenter.com/view_story.asp?ID=8070