between these two, for you I’d definitely recommend the Dopod for the following reasons:
1) larger screen size (0.4″ difference may not seem like much, but remember the screen is measured diagonally
2) keyboard, keyboard! I’d hate to imagine doing gmail/your company email without the QWERTY keyboard. (btw, mobile google is at http://m.google.com)
As for PDF/DOC/XLS, they are all supported by default in the 838pro. I’d imagine the Stealth would as well but I didn’t get a closer look. Keep in mind that Word and Excel mobile cannot be expected to be 100% compatible with your windows documents..