sealegs welcome to trt!!!!!!!!!!
I see you, like us, have been bit by the reef bug, welcome to the crazy club!
Just so ya know you have what is considered a small tank - I know it seems crazy, but 45 gallons to most reefers is still a nano
May I as what a filstar filter and the biowheel is for?
I think you could have about 4 fish in this tank
provided they are on the smaller size
firefish
gobies
blennies
cardinals
a reef safe wrasse - check tank allowances
clowns
damsels- though aggressive
dottybacks -
hawkfish - if you don't mind the shrimp being a snack.
to name a few
I think a 6 line is a great fish to have in a reef tank - they take care of pests and have fun qurky swimming patterns, plus a lot of color.
(speaks in a gentle voice knowing you aren't going to like what ya hear...)
the tang is too big at any size for you tank.

They need lots of long space swimming room to keep from being stressed - (think 6 ft long tank).
I highly suggest you take the tang or try a trade. I agree they are beautiful fish, but it will be prone to stress and therefor ich in your tank.