HTC 8125 / 8100 / MDA (USA) / K-JAM / P4300 (Wizard)

I would appreciate anyone suggestion to my dilemma. Briefly, in my line of work I travel extensively around the globe, hence I need a quad-band phone. The most important feature for me is the reliability of the device, decent (i.e. professional) looking phone with good audio, display and BT headset capabilities with enormous phone book and some miscellaneous PDA features, like hosting third-party database. As far as the internet features are concerned, I mostly has to be able to access my various email accounts as well as occasional IM. In light of the above, which of the three devices (i.e. 8125, 2125, Blackberry) would you recommend as my Cingular reps claims Blackberry would be the answer...
Thank you.