Get a TSI Flowmaster, cut the end down and drill new holes for your back axle, then make a custom deckplate as wide as you want, orrrr get a 5.0 Orion. Or wait for the Addict decks.
I would consider an Addict Deck if i were you. I have tried one. They are really light and if 4.5 isn't too narrow for you they have plenty of different lenghts to choose from.
I would have to say Stan's Reventon... I just finished building one up the other day. It is the first deck i have been on that I have the room i need, I have felt cramped on every other scooter ive ridden... I'm 29yrs old, 6'-1" 170lbs, and size 11 shoe.
It is definitely a little bit harder to whip and stuff but the extra length and width are well worth it
edit...just realized this is an old thread...opps whatever...