Need Passive Subs- Ideas?

I am using a set of Talon Khorus speakers, which I am using just for bottom end with a set of Unity Audio for the uppers. A DQ-LP1 crossover works well to blend them. It sounds great using that combo, but I need to sell the Talons due to the size and it just seems like a waste of an expensive speaker(just upgraded the networks too) to utilize for bass only. Anyways, I am looking for a good alternative as I do not want powered subs, I will use an acoustat amp to drive them. Would like to keep them against the wall due to somewhat limited space. Not looking for huge 15" drivers, as I prefer good tight bass, but really like the lows that the 10" Talons can do. I am a furniture maker, so construction shouldn't be an issue. Any good designs/plans or might even consider already made passive subs, would work out as well.