We've stayed at Desert Inn and Suites a few times with a group of 6. That was their smallest suite. We did have one booked that would sleep 8, but the trip fell through. The rates were always pretty reasonable there, and you couldn't beat the location. I just checked and rates look to be between $209-$229 per night for suites that sleep 8 and 10. There were 3 different varieties.
The Anaheim Desert Inn and Suites, Anaheim, California, Disneyland Neighbor Good luck! It sounds like a fun trip!