Go for N900 replacement or E7, E7 is quite complete when it comes to e-mail, PIM. Nokia e-series are business phone so they are of good quality and the keyboard is amazing.

I have my N900 for 2 years now, and never had needed to go for warranty. Probably, I void my warranty when I replaced the digitizer myself :P I think even without warranty the N900 can be fixed by your self