you should pretty much figure you wont get it rite the first time. you'll feel less stupid that way when something goes wrong. dont know how much from you know from your fw tanks but i'll assume nothing. you should definitely read a beginner book for some of the basics; it will help dull the confusion.
vets can correct me, but since i'm just getting started with my tank, i'll pass along a few of the basics that i've learned in the last few weeks.
the reason they ask about lights is cuz there are 3 basic components to SW tanks...fish, corals and rock. if you want corals, your gonna need the more expensive lighting. for just "fish" or "fish and rock", regular lighting should do just fine.
these guys can get carried away with their equipment .... most impt components are 1)protein skimmer, 2) powerheads 3) lighting. they love the lighting cuz they love their corals. its like underwater gardening
basic theory and premise behind reef tanks is that porous rock becomes a host or kind of condominium for bacteria which helps convert the natural waste of the fish into less harmful stuff. this is good and something you want to happen. the bacteria can also live in the sand. your at a website that focuses on reefs so these guys are all big propenents of the live rock (which is what they call it once the bacteria moves in). however, some of them think its better to go with no sand in the tank (barebottom) and some guys go with shallow sand bed while others go deep sand bed. supposedly u should either have less than an inch or more than 4 inches of sand, anything in between is a potential problem.
the process and time for the bacteria to move into and onto the rock/sand bed is called the "cycle" . when left to itself with no special chemical enhancements, it can tank 4-6 weeks for the tank to cycle. you should NOT put fish in the tank until the tank has cycled.
also....be very cautious of employees of local fish stores my reading and experience with sites like this one is that these guys are smarter and more experienced..plus they dont need to sell you anything to keep their jobs.
based on your initial list of stuff, i'd switch the amounts of rock and sand. more rock is better. the remora has gotten good reviews so thats a good choice for a skimmer for a smaller tank like your contemplating).
you need to get some powerheads to move the water. you should figure on 2 powerheads. their combined 'gallons per hour' of movement should be at least 6x the volume of your tank, altho most guys go with a minimum of 10x the tank. some go over 20x. the fish are use to lots of waves so they dont mind ... its like exercise for them. plus the water movement keeps the crap (formally known as detritus) from settling in the tank. i think most guys also have some form "mechanical" filter to catch that detritus. snails and crabs are excellent natural recyclers of detritus.
(they call the rock a biological filter).
most of em have such big tanks that they put most of their equipment in smaller tanks that they stick under the main tank. they call these sumps or refugiums. the guys seem to get pretty creative with pumps and pipes to keep the water cycling between the main tank and the sumps. its over my head at this point, but im hoping to graduate some day. thing i havent figured out is how to keep my floor from caving in from the weight of a double tank system filled with water sand and rock.
thats enuf for now. just remember that there are a number of different opinions and very little gospel. its an amusing ride.