I made this up real quick to help visualize what I mean. I figure this would be a good layout that can do you well. on the top and bottom the filter floss can be thicker but the middle one is optional and can be thin. It's just to catch anything that might remain before it reaches the main bio-media but that might be slim chance either way it will hold good bacteria. The bag of carbon or purigen can go above or below the biomax but I figure it's just easier to remove if it was on top obviously. you can even fill the top chamber with a bunch of filter floss and put all the bio media in the second one from the top if you prefer I just figure you can add a little extra media this way which means you don't have to clean it as much and could potential house more fish or have a faster recovery in the tank.
I'd also just clean the foam and filter floss for like the first 6 month and leave the rest alone or till they are slimy and clean only one section at a time when rinsing the media. Just take a bucket of water from the tank that you removed from during a water change and squeeze it real good and shake it around in it till it looks clean.. this should remove most of the particles from the foams without risking any chlorine being added to the canister.