if your just starting out, i would suggest you buy one of the master test kits, it should have all the basics with the old except of
PO4 (phosphate)
Master test kit just means its go most of the essentials in a neat package.
Are you just starting out in the marine hobby?
Are you aware of the
nitrogen cycle ? if not, thats your first port of call.
Understanding bactera & how it contributes & effects you tank will cover the first building blocks of testing, keeping specific species groups will cover another series of tests ( these tests are for the additions you add to the tank that are to target feed specific coral groups)
basicly, in my personal stereo typical opinion , if your just starting out, i would suggest you stick with softies for awhile, to kinda warm you up for the mass amounts of information to come.
makes testing easy with the master test kits & they can leave some room for error, which we all need when starting out.
as for specific kits, i'll let your fellow americans give opinions on the better in your market.