If you don't get a great deal at WL or AKL and do go the mod route, I would probably pick POFQ. I have stayed at all four mods and enjoyed them all. However, for the age of your kids, POFQ is a real winner. Its smaller, the pool slide is not as long and daring and I think on that slide, they can come down with an adult. They couldn't do that at the other mods, you have to be a strong swimmer (no life vest or floaties) to use the other slides at the mods. The boatride is a real plus to DTD and when POFQ shares buses with Riverside, it is picked up and dropped off first.
My personal favorite is CBR with CSR and POR close behind. However, my kids are 11 and 13, so my needs and wants are different!
I agree with cjsmom5 about the stroller issue at POR. Given the bus sharing, if you have strollers, and full buses it can be a pain. Transportation wise, the best mod is probably CSR. No bus sharing and since its a convention resort, many of the guests don't go to the parks and therefore don't use the buses. However the spread out nature of the resort might not be the best and the pool while wonderful is better geared for older kids in some ways. CSR does have a nice playground near their main pool and several quiet pools.
CBR is wonderful and the only moderate that has preferred location. So even though its huge, you can get a guaranteed room (costs a bit more) near the food court and main building. CBR doesn't share buses and its pool is good for little kids too. It also has a playground (maybe more than one can't remember) and six quiet pools. So in a sense, CBR would be my second pick for you if you go moderate due to the preferred location rooms, and the fact the rooms are the largest of any of the mods. In fact CBR rooms are almost the exact same size as the rooms at AKL and WL. No bunkbeds available here and of course the beds are doubles, not queens.
Good luck with your planning and upcoming trip!