I'd get a triathlon style race belt and find a way of taping the gels to it or something along those lines. I'm not sure if it'll work, it should, but if you get a race belt and go into your local bike shop and ask for some tubular tyre tape (it's double sided and sticky as hell) then you can put the tape on yout number belt and whack the gels sideways on that.
I use tub tape in triathlons for everything! energy gels onto the cross bar on the bike, under my inner soles in my running shoes to stop them moving when a sticky bare foot gets jammed in at high speed, same with my bike shoes. Ok so not quite everything, but it might be worth a try.
I'd start taking gels after 1 hour, In a triathlon I will take 2 on the bike one after 10 minutes, one after 40 minutes. So at 30 mins and 1hr into the race, don't take anythign on in the run section usually, but the higher pace makes it hard to get anyhting apart from oxygen in!
If you really want a hit of good stuff I'd recomend getting some Agisko, I'm not sponsored by them so this is a plug because it's amazing stuff! It has MCT's and a number of different natural sugars. You buy the gel in concentrate and make it up yourself. You can take a load of it right before you start and it'll be a massive boost to your energy supply. A 400ml bottle of concentrate contains 5000Kcal if my memory serves me correcty. If you dilute 50/50 then it gives you a lot of extra energy in your system before the start which will prolong your performance. I take the gel 10 minutes before the start of every big race and I have yet to not run a PB and feel good at the end.