I'm looking for a new phone. So I wonder if anyone could give me the best shot for these phones,

Nokia C6 OR Nokia E7 OR Nokia N900 OR SE Xperia X2

Well, I'm much of a qwerty fans as I am more to typing. Touchscreen typing is annoying to me though.

regarding the phones above, which one is the most reliable, lag-less, less error, durable enough for a student, affordable price or anything you'd like to add.

also, fyi, i am not an user in any social network site, so yeah. i guess, the only thing i need in my future phone is having a good internet access, document viewer (a must), organizer (note taking and stuff) and ... i guess that's all till now.

you can recommend me some other phones too if you want. the above phones are just the phone i just made review to it.

Thanks for the suggestion.
One more thing is there a phone that's similar to E7? Just wondering though, E7 doesn't have memory card slot but I need that. I don't really care about the camera as long as it's MP is decent and i can take picture with it. Sony Ericsson or Nokia will be alright.