Another vote here for staying onsite at a Universal hotel. Also, I would stay there the last 2 nights of your trip so you can get 2 full days in the parks without stressing that you have a flight to catch later. It's really hard to go from Uni to WDW because that unlimited express really spoils you quickly.

It's so nice to not have to worry about FP times or availability. So for that reason we do WDW first. jmho.
I have found if you stay 3 nights at a time when they're offering an AP discount on hotel rooms, buying the AP simply for the hotel discount will pay for itself. It knocks about $100/night off the hotel price and not all guests in the room need an AP; just 1 guest.
To see if your dates have AP rates, use promo code APH. Like Disney hotels, Fri/Sat nights are more expensive.
AFAIK, there is no benefit to booking as a package, so I usually just search hotels on Uni's website. For tix we buy at
Undercover Tourist.
If you sign up for email alerts, they'll send you discount offers. We stayed at HRH in Sept with a coupon for 35% off but it had to be a 4 nt stay. Not sure if that would wreak havoc on your Disney plans.
Over the years we find it's hard to do both so we now do separate shorter trips.
