The Grand Californian is, as Wish stated, Grand!!
Seriously, if you can afford to stay there, do so. It's actually the best of the three, and has access directly to California Adventure..
It's much more compact.. No busses per se, with everything within walking distance.. A few rides not found in WDW, such as the Matterhorn, Pinnochio, and the Buzz Lightyear is much cooler!
You won't necessarily need a rental car, especially if you're staying on Disney property. There is transportation to and from the airport, and LAX is probably the cheapest, though Orange County or Long Beach airports are nearby..
Storyteller's Cafe is the best, there are character meals, a lot depends on their ages..
Seven days is more than enough, and you will have time to go to both parks, as well as go to San Diego if you wish to do Sea World or other non disney activities..
They do accept Disney Dollars in Disneyland, and it is about 35 miles between LAX and Disneyland..
$1,000.00 is more than enough to feed a family for seven days, especially since there are numerous restaurants within walking distance that aren't overly expensive..
I've heard that the concierge category is well worth the difference.
Hope this helps..
