Well, since you have young kids, I would imagine that you will spend a lot of time in MK, so....if you are leaning towards a deluxe, you could try the Contemporary. It's on the monorail and you can walk to MK, via the path..it takes less than 10 minutes to do it. You can take the monorail to the next stop, TTC, and change over to the Epcot monorail line.
The Polynesian is fun and you could take a boat to MK and walk their path to the TTC for the Epcot monorail.
Or the Wilderness Lodge is terrific. You can take a boat to the MK. Buses to other parks. The Wilderness Lodge is a bit less expensive than the other deluxes. As is the Contemporary.
Now, if you opt for a moderate, there are some great choices. POR is terrific. Nice arcade, good food court and a table service restaurant. The rooms are a bit smaller than the deluxes. The main pool area does have a water slide that's perfect for the littler ones. THis was my dd's first water slide when she was there for her first trip to WDW for her 6th birthday!!! Now, it's pretty tame to her at the ripe old age of almost 12!!!
Beach CLub does have a terrific pool area but it is sometimes hard to keep track of little kids due to it's size.
And the values are great fun for the kids. My dd has stayed at POR, Contemporary, Polynesian, AllStarMusic, Pop, Beach CLub, Boardwalk.....although she loves our home resort of Boardwalk, she loves the theming of Pop and AllStarMusic!!! The rooms are small, just a wee bit smaller than the moderates.
Up to you....you are right, so much to choose from. Try to narrow it down a bit and we'll try to help some more.
Oh, and welcome to the DIS boards!!! This is a great place to learn and to share your knowledge. You'll be sharing info yourself before you know it!!!