I have a wet/dry I turned into a sump (for the time being) I completely agree with not having bioballs.. they are a disaster waiting to happen.. I threw them all away and replaced with matrix.. I know this isn't live rock but at the time I only had enough LR for my DT.. when I grow up and get a real sump.. I will be replacing the matrix with the tons of LR I have collected since I started this hobby.. I use the blue media in the tray and if need be you can add phosban or whatever if you run into a problem right on top of the floss and below the trickle.. on the empty side is where I have my skimmer and pumps for my sump and reactor and skimmer.. very tight squeeze but it works for me.. again until I can get what I want.. that is a rimless 100 gallon long with a nice sump to accommodate..

so great job with the score on the wet/dry!! You can always change it out later if you desire! Just stay away from the bioballs!! Good luck with your set up