For a FOWLR
I'd use a HOB
filter just because it will give you more options when it comes to what you want to add Carbon, copper, phos. pads can be placed in a HOB
in seconds You can use treated water but after a while the minerals will build up in the system causing problems long term. (RO
is your friend)
Most of your bio filtration will come from your live rock A skimmer aids in the removal of proteins that cause algae growth while adding oxygen to the water. you'll want one.
As for lights any light will work. If it were me i'd buy good LEDs now ones that can support SPS
I'll bet most every one here started with a FOWLR
. Then spent even more money upgrading there lights
One thing in this hobby buy the best you can the first time out Upgrades cost to much!
Flow looks a little low maybe two 850's you want to keep any junk floating so the filter remove it. Oh. and drill that 55 you'll thank me later