Unfortunately, with regards to the passes, you probably won't be able to find much of a deal. Discounts are available on multi-day passes but not on single-day admissions.
My best advise would be to purchase 2day/2park passes at WDW. You cannot purchase them in advance; they are available only at the gate. You will not be able to "hop" between parks with these passes. You will have to choose 2 parks and spend 1 day at each of them. The passes cost $105.43 per adult (anyone age 10 & up) and $84.14 per child (ages 3 to 10). Those prices include taxes.
At Universal Studios, you can get a break on multiday tickets but I haven't seen discounts on single-day passes. A single day adult pas is $57.46 (with taxes). A child's pass would be $47.87.
However, if you want to spend more than one day at Universal, you can get 5 straight days of admission for the cost of less than 2 single days. You can buy 4 5-day passes and get the 5th free for the cost of $383.19 (including tax) if you have a Mastercard. That translates to $76.64 per pass. To do so, follow this link:
Universal Buy 4 get 5th Free Offer
You can also order them thru a Kraft Offer that will give you the same passes for $87.28 each (with tax). You can order a maximum of 4 of these passes at a time thru this offer. Follow this link for the Kraft Offer:
Kraft Universal Ticket Offer
For helpful suggestions regarding touring the parks with a child afflicted with autism, visit the
DISabilities Message Board . There are some great people who can answer any questions that you have.
Have a great trip.