100g display with 55g sump

[Rumble Fish]

I originally posted this under the DIY section but realize this may be the better location...

So, I'm starting a 100g freshwater tank project and will incorporate a 55g sump.  I'm going to keep it low tech with LEDs in the 5000K range to allow medium light plants to grow.  I'll be moving my clown loaches into it and definitely introduce some angels at some point.  I'll probably round it out with a couple (or three  ) larger groups of tetras as well.  This tank is twice as big as any I've ever had before so my mind is literally overflowing with all the possibilities here!

I tend prefer slower growing plants (java fern, crypts) in general, as this usually means less maintenance but now that I have such a large tank I'll definitely include swords, vals and lotus and I want to try madagascar lace too.  All should be ok under this light spectrum, I think.  My sump tank will house faster growing, unrooted types strictly for biological filtering.  However I plan on adding these after the display plants are growing well and the fish population warrants it.  I have no doubt I'll eventual be overstocking 

My plan for the sump from left (where the water enters) to right (where it is pumped back to the display tank) is to have a wet-dry filter area with filter floss and pot scrubbers / baffles / a larger, open area in the center to grow live plants and install the heater / baffles / then the pump.  I also want to incorporate a Hamberg Mat Filter (HMF) into the design.  My intent is to provide maximum surface area to allow as much beneficial bacteria as possible to grow.

My question:  would it be more effective to install the HMF just after the wet-dry filter or just before the pump? 

My thoughts:  If I place it just after the wet-dry, the mat has access to the highest bio load which hopefully translates into a healthy mat.  If I place it just before the pump then it then it has the least access as all the mechanical and biological filtering is before it but the sump plants should be healthier (and they should therefore be more effective). And by placing it last the HMF will provide a clean polish for all the water passing through it, if nothing else.

Good news, my hole saw is finally in so I can plan to drill soon!  Then I'll need to get some acrylic for the sump baffles and the display tank weir.  Any suggestions here?  Ideally I'd like the acrylic to be cut for me as the weather is getting cold and I have to do this stuff outdoors...

I'll keep adding to this post as I get closer to finalizing my ideas and work progresses.