If you intend to do a reef, I would avoid the canister as they tend to trap detritus VERY well and if you are not extremely diligent, can result in high nitrates. IMO
, a hang on filter like an AquaClear (now called Fluval) is a better choice and ultimately easier to maintain if you're not using a sump. Here is a link to a video I made explaining my sump.
Aquarium sump explanation - YouTube
"Reef" indicates that you are keeping corals and is a certain type of saltwater or marine aquarium. This type of aquarium requires more intense lighting and higher flow as opposed to a "FOWLR
" (Fish Only With Live Rock). "Marine" and "saltwater" are interchangable terms in my mind. It's not so much as what the label on the test kit says, as what you test for. You want to be able to test for ammonia, nitrite, nitrate, and pH at a minimum. If you go reef, then you'l want to add on calcium, alkalinity, magnesium, and phosphate. Use a refractomer (more accurate) or a hydrometer to test specific gravity (salinity).
You don't need a skimmer, but I would highly recommend one. Avoid the Coralife Super Skimmers and the SeaClones. They're cheap, but not very good. I'd also consider a pair of water circulation pumps. Koralias are reasonably priced and well built.
I do recommend sand over crushed coral. Many folks feel like buying live sand is like buying snake oil. You can buy live rock or dry rock (cheaper). Dry rock is considered more ecologically sound, but you don't generally get any neat freebies (worms, feather dusters, etc.), but then you also don't get any pests (bobbit worms, aiptasia, majano) either.
I'd ditch the damsel (mean), dottyback (often mean), and mandarin (difficult to get to eat, especially without a refugium). Switch out the bicolor dottyback for a royal gramma. Same colors, generally cheaper, not as mean, and actually a little more atractive in my opinion. As far as the clowns, go with skunk clowns, ocellaris, or perculas. The others tend to be mean as they get older. BTW, no anemones without high intensity lighting and having the aquarium established for a minimum of six months. Waiting longer is better. The clowns don't need it, and many captive bred ones have no clue what to do with it anyway. Anemones also tend to sting corals.