I'm curious to see how the 100 micron/25 micron combo works out for you. I currently only have the 100 micron on mine and bioballs in the second, but I'm not sure if I really need the extra bio, so I might eventually switch it out for a 25 micron cartridge for better water polishing.
Anyways, I was hoping to add a suggestion before you got everything set up but it sounds like you've already got it up and running. I think it would be a good idea to include a union or union ball valve between your pump and the the filters, and between the filters and the return so that you can easily take everything apart without draining the tank in the event that you have to do major maintenance. I ended up with some minor leaks when I first set mine up and I was really glad that I was able to easily isolate the filters from the rest of the tank to work on them without spilling too much water.
Oh, and I think I've said this before, but that tank setup looks fantastic. I love the cabinets and how you've integrated the whole thing into your home.