partyofive said:
Is Seaworld included in the hopper choi

ce?
No, Seaworld is run by a different organization. But if you'replanning any days away from the Disney parks, I wouldn't purchase WDW tix for those days also. For instance, if you'll bein Orlando for six days and wat to go to Seaworld on one day, then I would get the 5 day MYW tix and 1 day tix for Seaworld rather than double-covering 1 of the days. (Unless your kids will feel like going to WDW in the evening after being at Seaworld all day long -- mine wouldn't. Or unless you want to squeeze in more park time on a day that you arrive or depart.) Basically, I'm saying that unless you get the Non-Expiring option, you shouldn't pay to have extra park days that you won't use.
You haven't mentioned what time of year you'll be going or the ages of your kids. If you go in July, the parks are more crowded and you may want more days so that you get to see/do more. In January (after the holidays), the parks are less crowded and you can see/do more stuff in less time.
For a first visit with young kids, I would plan on 5-6 days at WDW with park hopping priveledges and maybe throw in a trip to Seaworld, if that would interest them (in fact, that's my general itinerary for our upcoming trips -- 6 days at WDW in April and 6 days at WDW and 1 at Seaworld in Sept). We plan 2 days at MK, 1 each at AK, MGM, and Epcot and one day left open to do/see anything we didn't already and/or reride our favorite rides.
With older kids (preteen/teen), I would definitely consider Disney Quest, one or more of the Disney water parks, and/or Universal Studios.
I hope this helps!