As you know, the more filtering the better. For my 150 gallon with a pair of pups I have my sump with a mix of bacteria house, some Japanese mat, and bioballs; I also have an eheim 2217 run in a loop off the sump to polish the water in the sump.
In the sump for my 300 I have four trays of Bio-home; a couple trays of filter floss as a prefilter, and two bio-wheels. I also run an Eheim 2260 loaded with bacteria house on that tank. Finally, I have that tank set up on a 10% water change per day drip system through carbon filter (for drinking water) and a drain from the sump.
My advice to you is to try and figure out a way to get a drip system running.