HEED seems to be the way to go, as far as research online goes. I will stop by MOAB this week and see what they have. I havent experimented with gels yet, but I have a feeling it will come sooner that later.
I have had good experiences with the OS Cycling products, such as pre-load, re-load, and Endurance. I use it as my main drink for 12 hour / 24 hour races and long road rides.
I use the OS Sprint for cyclocross races.
Moab stocks it and it comes in individual packets so you can just get a couple to mix up some bottles to try for pretty cheap.
Never seen the drinks like Accelerade or otherwise do much but empty my wallet. The OS stuff is interesting, but personally I've had a harder time handling those during a ride than overly sugared Gatorade.
I'd try mixing the cheap but superbly effective Gatorade to a tolerance you can handle, as mentioned above.
The OS has been my favorite. It isn't too sweet. It sticks with you. Tons of calories in just the right form. To top it all off, it was created by some local boys.
Well looks like I will be making a trip to MOAB tomorrow, I was three miles into my ride today and the back tire went down. My luck is that I dont have anything at home to fix it. So I will be picking up some OS and some of the smaller packs of drink mixes.