I'm planning on getting a Smartphone or PDA specifically for browsing and email
when I don't have access to a PC.

I currently have Verizon service on my cellphone , and am very happy with it.
I may get a BlackBerry device.

If I go with a berry , I would have a choice between Verizon Email service or Blackberry.

Can anyone Enlighten me on the advantages/disadvantages between the two ?

well i have to say the blackberry browser isn't that great unless you have  BES server at the office to attach it to. Same with the blackberry service, no BES server and its probably not worthwhile as long as the verizon mail works well for you. It its similiar to the sprint blackberry web mail thing (you setup the sprint server to hit your personal mail account via pop/smtp) then it'll be sufficient.

I'd also look at a treo 700w. Much better browser than most of the BBs (I run the BES at work, we have about 150 BBs and 200 or so windows mobile phones) though somewhat more expensive. Most of the BBs we have are sprint though a few are verizon, we use the full bes service though as we have a server.

While I don't have the treo personally (i'm on cingular) a friend has one and its pretty sweet. Additionally if you would consider moving to a different network a friend of mine has the cingular 8525 and its damn nice too. The internet on the 8525 (when you have 3G coverage) is super fast, in testing its gotten 700k to 800k on the device and also on a bluetooth tethered laptop.

whatever you do, make sure you get bluetooth on it and if you have a laptop with bluetooth and the right service plan you can use whatever device you have to browse with the laptop.