Lol... yeah I know the feeling, actually you shouldn't have to buy another wide angle lens, because the 5D would make all your lenses appear shorter, IE, your 50mm lens on a 40D or digital rebel would act like a 80mm lens but on a 5D it would act like a true 50mm lense, so all the lenses you have now would be more wide angle than they were before with the 5D, if anything you might need a longer zoom lens
Good luck with it dude!
Paul