Hi Possum Hopper,
You are a bit faster than me (my pb is just under 4h and on a v. flat course) but it's not that big a deal where you start. As Carmen can tell you (having trundled past me every year 
).
As STFC said you don't really need to carry food & drink. Maybe a water bottle at the start, as the first few aid stations are a bit mad. But bear in mind there are no portaloos IN the start pens (where you'll be spending 30 mins to an hour). So keep it for if you're thirsty - don't end up like me with cross eyes in the start pen and searching desperately for the loo in the first few miles!
All the aid stations - which are less than 2 miles apart on average - have water and Energade (not Powerade iirc) in the biteable sachets. (Don't squirt the former on you to cool down, it's sticky!). They give out free Energade in the international athlete's corral at the expo so you can try it ahead of time.
Also there are little cups of cola (Pepsi I think).
On the later stations (half way ish and onwards) food starts to appear. Orange segments (not salted!) - sadly I find these don't agree with me when running though they are yummy. Salted boiled potatoes - om nom - and bananas, and biscuits. It's easy to blag other stuff off the spectators and there are "unofficial" aid stations too (e.g. iirc sandwiches, and salt on its own). I could not find lemonade or barley water for love nor money but did manage to sneak a swig of beer off one chap 
Don't dip your water bottle in the troughs - not hygienic - they are for dipping sponges etc in. Lumps of ice are also given out - can be stuck inside lycra gear to cool you down (worth the slight chafing that may result).
Definitely worth experimenting with which of the above you can eat on a (Comrades pace, much slower!!) run. Sickness gets lots of people (inc. me in 2011, v. grim). It is way way different from a marathon, apart from that thing of the first one being a big learning experience.
For each headline time there are several buses. I seem to recall at least 3 for 11 hours. But the thing is that you will have good patches and bad patches and trying to keep up with a bus in a bad patch, or wasting time slowing down to stay with one in a good patch when you could comfortably go a wee bit faster, well, neither is ideal. Better to use them as indicators and not worry too much about them unless you find the last 12 hour bus at your heels!! Remember they are "driven" by humans too, and are not foolproof.
Best of luck. It is a compelling event and a great challenge. I had a lousy time for some of my first (the middle 30k was fun, mind!) and still came back for the down run the next year. Down run much easier if you like downhills - which I do!
