BlackBerry Forums Support Community - Tell me more about BES hosting

I'm helping a non-techie friend get set up with a Blackberry now that he's no longer in the warm corporate womb. He'll probably be on verizon. I'd like have a domain for him and was going to get it hosted by Yahoo (a mail interface he's familiar with) that would autoforward to his BB and his email would read [email address]

But I keep reading stuff around here about BES hosts like Mailstreet and EOutlook. I don't quite grasp what under circumstances I should be considering this. Would this be the most seamless way to set my pal's life up so his email looks professional and not "david@verizonwireless.blackberry.net"? Money is not an issue. Thanks.