This is the exact set up I use on my heavily stocked 180g. With the AC110s I use the sponge(rinsed weekly in hot tap water) and the biomax(rinse only tank water) and have saved the carbon for when needed. You can buy lift tubes for undergravel filters to extend the intake of your AC110 near the bottom of the tank, unless you are using sand this will help remove more solid waste.
The XP3 I fill half the bottom basket with either Fluval prefilter or ehfimech, these are ceramic rings but not for the beneficial bacteria to colonize. Then put 2 coarse sponges to fill the rest of the bottom basket up. In the middle basket I first put in the two medium sponges then a divider and fill the rest with either, biomax, ehfisubstrat or matrix. The top basket is filled with any of the three prementioned bio media used in the second basket. I don not use any micro filtration pads. I have a total of 4 xp3s set up in this manner. Place the intake at mid water to minimize the amount of particulate waste taken in. I clean my xp3 on the 180g once every 3 months.