Skimmers
Bubble Master, Bubble King, H&S, Deltec, Euroreef, and ASM. Those are the most user friendly units available. Needlewheel technology is the most efficient and cheapest to operate. Beckett injectors are ancient technology, like undergravel filters some people refuse to adapt. Becketts are ok in that they do work but need huge high wattage pumps. Personally after spending $1,000 on a nice skimmer I'd like to save some money on the operating costs. ASM being the most economical. Euroreef being easy to find and affordable, step up from ASM. Deltec are available, pricey but well worth it. the rest are like Ferrari's, expensive but oh so nice.
Return pumps.
Reeflo Dart. Most economical and quietest of external pumps.
Eheim being the best and absolutely silent of the submersibles. I heart Eheim.
Others, MagDrive, coralife, Iwaki, Blue line
Lights.
Icecap ballasts, PFO ballasts. Sunlight supply for ballasts and fixtures. Retrofit kits from HelloLights.com are affordable and nice. you'll need to decide what is going in the tank. A tank that large I'd recommend at least 3x 250w halide with about 200w+ of T5 actinic lighting in TEK reflectors for a reef. flourescent fixtures from Hdepot will work. CoralVue ballasts are known to burnout early.
Flow.
Tunze pumps are awesome. I won't use anything but Turbelles and wave boxes.
Other brands of interest, Hydor Koralia, Seio.
Sumps or refugiums
Stay away from the over priced Oceanic units. TriggerFish systems makes beautiful sumps but they might not be large enough to house a skimmer appropriate for such a large tank. Rubbermaid feed troughs from livestock sources work great and are affordable for your tank.
Chillers.
Pacific Coast imports. Sunlight Supply. Teco. Current Prime.
salt mixes.
Tropic Marin, Seachem for reefs. Instant Ocean for fish only.
Caribsea Aragonite for substrate. 300lbs of live rock.
An old calculator said to expect $50-100 for a beautiful reef tank per gallon from new. That was for everything: tank, stand canopy, lights, filtration, chillers, heaters, etc.... Fish only setups are cheaper and just as enjoyable. Best of luck.