Lighting:
A few VHO will more than enough and VHO just because of the depth.
Skimmer:
I personally would not spend more than $500 on a skimmer for this if even that. I personally would go skimmerless and just do good water changes more frequently maybe.
Flow:
Larger tanks with FO need good flow also, I would get 3-4 tunze streams. Maybe one on each corner pointing in different directions or get a single close loop with a sequence pump. If you are not going to have a equipment room behind it, I would seriously go with the tunzes instead.
You will need a chiller to keep the water on the cooler side,which prevents disease in FO tanks especially with larger angels and butterflies. I pressume you are going to use LR? Are you getting a larger UV unit? like 150+ watt? I would to prevent algae and disease. I would also get some kind of mechanical filter even if it is some filter socks in the sump. Finally, get a 300g or so water storage tank so you can always have enough water for larger changes once per month.