Hmm, if I have a 50gal and money isn't an issue, I would have something like this:
70lb LR
50lb LS, 20lb dead playsand
Protein skimmer
250MH with 2 strips of VHO combo (That if you are going into reef)
2 maxijet 900 powerhead, 1 maxijet 1200 powerhead
I would have a sump if possible. This requires your DT to be drilled and there's always some risk drilling your tank. You maybe able to get away without having a canister filter or other hang-on filter running 24/7, but you wanna have a hang-on filter just in case if you wanna run some carbon or other stuffs for your tank.
Livestock:
2 perc clowns
Clown goby
Sixline wrasse
Flame angel
Hmmm, I enjoyed imagining myself having a bigger tank and money isn't a problem