With all that lace rock, and the concern about losing tank space to a thick background, I'd consider finding a mirror the right size to fit behind the tank, or have one cut. The background would then be the reflected back sides of the lace rock, you'd have a better view of spots where fish can be dead behind a rock, and any "sore thumb" equipment can often be obsured by running an airstone by it. It will also make the tank look twice asdeepwith twice as many rocks, but the downside is you have to keep the back glass clean.