To me a sump is a must lets you get things out of the display and increases water Valium.
Add in a refugium to the sump for nutrient export makes it even better as for as your canister i don't use them may be alright to occasionally palish the water. As far as lighting you need to get some ideal whit you wont to keep metal halide is the one for SPS tank but you can keep some SPS with VHO are T lamps. florescent T5 and VHO will let you keep all but the hard to keep SPS. power compact florescent is good for soft coral and most LPS. [jmo]

Theres a good thread hear on sumps