It depends on the brand and the niceness . I for one bought a marineland DD and got a heck of a deal on a very nice tank stand canopy and lights... But later (see my thread) my tank starts to leak and I had no warrantee... There is something to be said for buying someone else's issues... Seems like the going rate for a used tank is about a dollar a gallon... Everything extra makes it more but make sure you go on a ton Of forums before you buy, better ideas of what's out there and how much it costs. Oh and decently google "bean animal" overflows... If i could pick an overflow knowing what I know now that would be it.
Drains: holes with bulkheads that lead to the sump... Can be in the back but most of the time people bottom drill.