OK, I may be a SWF BB junkie, but even I don't read posts at 4:56am on Sunday! Don't forget time zones, and give folks a few days to get back to you!
As Godzilla says, Size Matters. You should search and read posts on the number of inches of fish per gallon- more opinions and information than you can imagine.
The brief summary- 1 tot 2 inches of fish per 5 gallons is the basic rule of thumb. Now, more smaller, less active fish will de better than one or two large, active swimmers. Bottom line is your Tang will eventually outgrow your tank- even if we was your only fish, they need more swimming room than a 60 will provide.