Edit, pretty redundant to what Elite and Semi said, but they posted so quick!
1) How big is your system (sump?)
2) How willing are you to do consistent water changes?
I'm a big believer in minimal supplements if you can do consistent water changes (10-20% weekly). If you have a large system, getting all the bells and whistles might be a good idea, since doing a 10% water change becomes a lot more involved/costly. But if you can get fresh salt mix in your tank every week, LPS will be happy, especially if your mix has good # in Ca and Mg.
I just use IO, Ca in fresh mix comes in at ~400-420 on my tests and will drop to 380 by weeks end. Trying to keep it above 430 has been tough for me in balancing (keeping consistent) Ph and Alk.
I'd say skip the ozonator and concentrate on good water flow and oxygenation (skimmer or cascading water).
Phosphate reactor, skip it if you can do water changes, unless you like the smell of hydrogen sulphide
An ATO is nice if you have the space for one (I wish I had room for one more 5gal bucket!).