Since you've cruised before, you are in a good position to decide what you want/need.
On our first cruise, we had a verandah which we didn't use (it was too hot.) Since then, we've cruised in several different categories. There are nice things to do with a verandah--hang out while little ones nap, have a romantic breakfast, etc. However, if you don't want/need it for those things, you can save a bundle with an inside cabin (cat 12 which usually becomes an 11). Only you can decide--do you spend much time in the cabin????? A porthole is nice, but if you're basically using the cabin to sleep and dress, it won't matter much.
Another thought--you can rent points out at about $10 each. Usually, it is a better deal to rent your points to someone and use the cash to buy the cruise. See the DVC boards for a lot of info on renting out your points.