Steve, I also can\'t eat and run (a fact that puts me right off full IM distance).
Woah! 4 bottles!! that\'s a lot of weight!! Do you think you can get away with just 2x750ml bottles? or one if you\'re feeling brave. I\'m guessing they\'ll have bike ready bottles at water stations, therefore, you can use bottles you\'re not fussed about and chuck them when you\'re done and pop the new ones straight in - or if not, when you finish a bottle, take off the top and put it in your pocket and when you get your new bottle, pour the water in - you\'ll loose some of it, and you\'ll have to slow down a little, but you\'ll probably only loose seconds (less than you\'d loose hauling the extra weight)
Also - I recommend you find out where the stations are and calculate when you\'re going to fill (maybe allowing enough to make it to the next station if you drop a bottle). I\'ve heard say that you should aim to drink 750ml every hour, which means for the time you\'re thinking about you might get away with 2 bottles to start and 1 refil en-route
Eating - I tend to have a little something every 30 mins whether I think I need it or not.
If you\'ve been training and done an Olympic distance I don\'t think you\'ll find the extra distance too difficult with the right drinking and eating (until you get to the end of the run and if you\'re anything like me, with 2 miles to go you won\'t care if the drink supplied is Gatorade, Go, Coke or lemon barley water, you\'ll take whatever is there!!)