a wet/dry filter is basically a bucket of media (usually bioballs) with water pouring over it. this is good for denitrification, but in a reef tank, it is not sufficient for removing nitrATEs
A better solution is a sump with live rock (or live rock rubble. hirocks.com has good cheap rock that will work well) which is kept WET, not wet/dry. also this is a lot cheaper than a wet/dry setup.
A skimmer is a foam fractionator, which fills a column of water with tiny bubbles. these bubbles attract DOC
's which then are released into a collection cup as they pop. This is IMO
a requirement for a reef tank. Better to save money by not getting a wet/dry and get a good skimmer instead.
MY main advice is to read this site for a few weeks before buying anything, especially from an LFS
. they will overcharge you for everything, and often give very bad advice. take your time. learn everything you can. look online for deals, especially on things like skimmers.