Pay a la carte, don't go for the package and only do it on rides that really need it.
Peter Pan is almost identical to the US versions, so you probably want to skip this ride either way.
Autopia can be skipped too with your party, for the kids and slow offloading. Cars road trip is for 5 year olds who love Cars, and can probably be skipped too. And Orbitron which is a Dumbo ride.
Maybe skip Buzz lightyear, depending on your competitiveness
If possible use single riders line on Space Mountan, Indiana Jones and Ratatouille (or skip this one because the Epcot version is so similar).
Phantom Manor always moves quickly, so lines are usually not that long to get a pass, Indiana Jones is in a hidden corner with a high height requirement and is usually not that bad.
That leaves you with Crush, Avengers, Spiderman Tower of Terror, Star Tours (haven't done these in years, no idea about lines), Big Thunder Mountain. With these it will be most beneficial to buy a pass.
I would start in the studio, ride Tower of Terror without, get a pass for Avengers, Spiderman and crush (not necessarily in this order), go to the other park buy one for Big Thunder and play it by ear from there.