For the monorail line hotels, I would recommend Poly over GF and CR as it is a very child friendly resort. The beach, the zero entry pool, the splah fountain area, Ohana's restaurant etc... My 3 yr old dd had so many other kids to play with there and it was fairly nice being on the monorail.
With your kids ages I would pick WL over AKL as your main park will probably be MK and it is only a fun boat ride away. AKL as fun as it is, is very far out there and you will have to bus to every park.
For moderates, most of them are very spread out which may mean a lot of walking. I have heard positives about Port Orleans Riverside but I have not been there myself.
For values, Pop seems to be the clear winner here as it is newer and doesn't share buses with anyone which is a plus.
You could also look into renting DVC points from a member and stay at a studio or 1 bdrm. If you do this, I would highly recommend OKW. It is very big and quiet and although everyone raves about the buses, monorail etc.. I felt that a rented car parked literally right outside our villa door was a godsend on our trip when dd was 2. Parking was free and we rented the car for $120 for 8 days. dd would fall asleep on the way home in the afternoon or night and we would just transfer her when we got home. We stayed in a 1 bdrm with full kitchen and full laundry area for less than a value hotel. Very worth it from cost and convenience. She napped everyday and we had the living/kitchen area to ourselves. We had a light breakfast every morning and early dinner after naps before heading back out which saved a ton of money. We did do the bus to MK from OKW one time and it did take much longer. I was happy to have the car and will probably do this again the next time we go.
Even at Poly the past week, I wish we had a car, it took us 1 hr and 10min to get to the AK from the Poly bus stop waiting to hitting the tyrnstiles in AK. Way too long in my opinion. Also, a side note. If the monorail is busy, everyone collapses their strollers and you hold the baby/toddler on your lap, sorta like the buses anyway. The monorails are great, don't get me wrong but it gets very tight in there sometimes. We liked the boat transportation from Poly to MK much better
HTH - good luck with your decision