I'm not sure adding the wood in the center like that is advisable. Would it look nicer if you had 2 opposing placements or off set to one side ???
My 180 has a similar wood set up and angles etc, but it set off to one side of the tank.
2 separate groups might be nice also.
You need to seal the inlets for the sump so no gas exchange can take place where the water comes in there, bag filters stink for this reason in most sump designs.