If you look you can find black elbows or paint it black. If you want to go open bulkhead I would do an over flow box to set the height
https://www.monsterfishkeepers.com/...ome-help-with-noise-reduction-options.680720/
Here's the thread on my 220. It will probably answer most of your questions.
I definitely recommend a sump.
Drilling is easy.
Don't spend the money on the H2Overflow items, just get the cheap stuff from BRS and PVC Direct (they have most fittings in black).
Go with three 1.5" overflows and two 3/4"-1" returns.
Don't get cheap pond pumps. I recommend a pair of the Jebao DCP 8000's, which can be turned down with a controller.
Ask away with questions.
How come you are recommending 3 1.5" intakes? Don't think 2 is enough?
Also, did you get yours to be silent? The biggest recommendation I found when you don't have an overflow box was that you should be using a T connected to the bulkhead with a cap drilled. If you do a 90 degree elbow the noise is suppose to be horrendous. Is that your experience?