The choice of what kind of media to run in ANY filter, let alone this one specifically is a matter of what you plan to do with the tank.
If you are doing just a small FO system, then you want to run the balls, the ceramic, etc.
If you are doing a reef, then I'd put at least 12 lbs of rock in there, and run the foam only.
I started with a 12DX on my nano and moved to the 24, but I did the same thing (proportionally) with both tanks. I put at least 1lb/gallon of live rock into the tank, and ran only the foam, only in the first chamber, skipping the bio balls, carbon, and ceramic. Then I slid my heater down into the 2nd compartment. This setup has worked great for 3 years and 2 tanks now and I haven't had a lick of trouble.
By the way, throw out the junk pump that came with your tank and put in a Maxi-Jet 600 or 900 in there instead. The stock pump has a tendency to not start back up after a power failure, and has bearing reliability problems, and you'll never find spare parts for it.
Also, if you didn't get the surface skimmer attachment with the tank, get one, it's worth the 8 bucks.