B-Ionic 2 part is a very popular supplement as is the powdered calciuim supplements. Personally I like B=-ionic as it has worked perfect for me, and its the only supplement I buy or use..... I konw others are gonna dissagree, but I would sabe my money on the test kits you list and go with PH, Nitrate, Nitrite, Ammnonia and Calcium and ALK...forget the others like PHos and MAG. Personally if you have a tank with sufficient live rock and its not overloaded with livestock (fish) I owuld probbaly forego the NItrate and nitrite and ammonia test kits as well. It woul dbe a rare thing if fish are fed properly and ro di water is used, to get phosphates built up, or nitrite or ammonia.......Even the PH is gonna balance it self out once a tank is matured and calcium and alk levels are in place. NOw if you have a bare tank with just a little or no lr etc then I would go with ammonia, ni and na tests kits as well, but calcium certainly would not be any concern then either. Test kits for the most party are not needed no where near as much as foks say they are once a tank has been up and running for awhile,and odds are most folks unless they are paranoid or doing excessive feedings and cutting back on water changes etc your test kits will long expore before half of them are even used.....I have not done an ammonia, PH, NI, NA, Am test in over 6 months probably more....I test for calcium and alk once every 2 weeks, and thats it.....Some folks use a test kit up in a months time.....no need! Flame away on my inept fish keeping but it works, trust me.