When I am on longer training sessions during the year I usually use a sports drink that supplies some protein with it (accelerade), since the 4:1 ratio is supposed to be best for increased endurance. My question is since most of the IM races only supply gatorade at the aid stations (at least that I am aware of) is it bad to train my body to get used to this sports drink if it is not available when the big day comes????

Short answer yes. If you are dependent on a certain type of nutrition, and the race doesn't supply it, then you should bring your own. Or, get used to what the race supplied. Your choice! There are many folks who carry baggies of powders that they throw into their aero bottle and add water at aid stations, OR, they have bottles premixed on the bike.

Run is a different story, but by the time you hit the run, you should be able to make do on less calories per hour, so load up on the bike, and then just drink Coke! (IMHO).