ataylo13, I'll throw in my 2 cents.
I have a 65 gallon tank, very similar towards your 58 only taller...I have at least 100 lbs of rock, DSB, and sps/lps and softies.
So:
1- Rio....in dumpster. I have a Mag 7. I feel that it's sufficient, although I do have 3 powerheads in the tank.
2- I"m currently run 2 175's 10K, and am pretty happy with it.
3- MINIMUM, get a 20 gallon sump. I have a 20 gallon sump, and kind wish for more. I had a 15 g before and it would overflow.
4-the tube of silicon, 'not for use in aquariums', they put it on the label for legalities. They don't want to be responsible for an accident. IMHO, it's fine to use and have used it in the past, for putting up baffles in the sump.
5-10 g refugium is more than sufficent.
6-go DSB.
7- No need for a Calcium Reactor for such a small tank. Go with a Kalk reactor. (Just My humble opinion). I built one for ~$20.
Link to my DIY Kalk Reactor
8-Drill the sump. Worth every penny. I'd take desjardiniidj's offer.
9-Put some $$$ in the skimmer. I personally, like Euro-reef.
Just my opinions. Do with it as you may...
whirley