it depends on the size of ur tank and if u want it to be FOWLR or a reef tank which cost more especially the lights but it all depends on the size of ur tank.........i have a 50 gal tank and my light cost 250 usd and if u want a protein skimmer which i recommend i bought mine for 150 usd its a coralife (im satisfy with it though) sand, lr and powerheads depends on the size of ur tnak also
for FOWLR yes u can use that light that u have but if u want a reef tank metal halides or compact is a must (i have compact in my tank even thought its FOWLR im planniogn to make it reef next year thats y) but if ur planning for a FOWLR that light that u have is okay to use and you need to wait atleast a year to turn ur tank into reeef if ur plannign too
And why wait a year?
u need to stablish ur tank first and it takes that long for the bacteria to establishe ur could wait for 6 months, but in my opinion i would wait for a year just because