dafuq listen to me!!! get nokia E7-00 you will get really good tools for business, i know it, i've been using it almost from it first day and i've never had problems except with usb (thing is that you can't really use phone and charge unless you want to brick usb port)
wp is ok, but it's not winmobile and i am sure you know what i am saying...well, symbian is really similar to wm even ui...is somehow similar...you will see
used e7's are cheap now and for that 3 phones you can get like 6 e7's...