We went for the first time a month ago. We needed a good three / four days to do most of it. (Didnt leave the parks till 3.00 the day we went home) we spent nearly a whole day in Fantasyland but didn't rush around we done everything in there.
We spent about 5 hours in Studios then went back to the Disney Park.
So I would say as 4 full days so you can enjoy just wandering around and looking, not rushing from ride to ride to try and do them all! but I also think you need days to do other things other wise you might get park overload !!!So staying for 7 days should should give you plenty of time to do the parks, go to Paris and still give you a day or so to do other things (Val d'Europe, Sea life centre etc)
I would think it would be very busy in July so prepare yourselves for queues (although you can fast pass some)
The park is also open alot later in the summer but even when it was open till 8.00 pm when we were there if you have Children we never stayed later than about 7.00 and that was the latetest as we wanted to have a meal) and for us the children would have be to tired to go back into the park. (Obviously depends on the age of children if you have them)
We planned to go to Paris but didn't this time but will hopefully next time but lots to do there!
The first time you go you try to do everything! Next time we are there we will definitely want to do some things again. We didn't get a chance to do like the lion king show which we really want to do next time. And then there are other things that we arent bothered about
The first time is like a trial run for the next time!!!!!!
I loved doing all the planning and found the information I got on here great!!
Where are you planning to stay? How many adults / childen going?