Well, since you probably don't want to pay for data, you might look for something that has Wi-Fi. And since you'd prefer not using Widows OS, you can check out Nokia's Symbian or Sony Ericsson's UIQ OS. If you're sticking with T-Mobile, the you don't really need GSM 850. Here are some options you can pick:
- SE P990i
- Nokia E61, E70, 9500, 9300i
They all have a qwerty keyboard
If you want to research on some more options, you can use the Phone Finder on GSMarena: http://www.gsmarena.com/search.php3