Pretty muc what reef_raf said. As for the sump and pump, go as large as possible, you won't regret it. A large sump usually means a large refugium, and lots of space for equipement. A large pump will give you the flexibility to run different flow configurations on your tank. Simply putting a ball valve on the output of the pump would allow you to adjust the pumps output... cheap, but effective =).
This person here is shutting down a 170gallon tank... contact her for prices on her live rock, that should get you started off very nicely.
-Richer