beautiful
welcome to the board and a great addiction.
anythign you need, feel free to ask and we will try to help. unfortunately i must appologize for the ignorance of some others here. as i understand it, you and a few other newcomers are confused as well as upset with responses from some people. let me assure you we are not all like that and most of us dont care to see flaming. we willnot stand for it! please accept our appologies and ask more as you need it.
now on to your questions:
salifert and fastest are decent kits. make sure you have a minimum of PH, alkalinity, nitrite, nitrate and ammonia. there are others you will want and should use alter but these are essential
55 gallon protien skimmer, what if you do not mind my asking is your price range? definitely get the best you can afford. remora(by aqua c) and euroreef are great as are tunzi. for a 55 gallon, a cpr bakpak would also be a decent choice and can be boughtn for about 150 or less.
i owuld not use the skimmer til after your cycle completes(could be 6 weeks, 2 days or 3 months.
instant ocean is a good choice, they ahve had a minor prob or 2 int he past, but have made them right. for the most part though they have been very true to us hobbyists. which can not be said for many others.
your target is as mentioned. i like 1.025 or more(up to 1.026)
ajnd premix your salt water, circulate and aerate it for a good 24 hrs before adding it to your tank, you do not want to add salt directly to the tank.
if you want a good book, which i do reccomend. look for
the new marine aquarium, by michael paletta.
it is accurate, inexpensive and very easy to follow. it is more easy to follow than one of those for dummies books that they make for almost everything. and is laid out much like a step by step guide, with steps right up through to your stocking selection process at the end
HTH