Let me just see if I have the logistics down...
MLT: Electric turkey fryer being heated by a 1650-1800W heating element underneath the false bottom?
HLT is not apparent yet, but I would assume more electric from your wood stand OR that you will go no sparge.
BK is also not apparent yet, but same with the electric...
2 tier stand with a single pump or perhaps a single tier for a brutus 20 style.
Are you worried about the dead space underneath the false bottom? That is probably about 20% of your mash volume by the looks of it. I also wonder why the sparge ring for the mash recirculation. It also seems like you are taking the coldest water in the pot (the bottom) and placing it away from the element by recirculating.
Maybe I am just really confused.