Welcome... Well I'm assuming you have a tank already and it looks like you have made a good start. You have a dedicated fish room (a reefers dream) that awesome. If it was me, I would figure out if I wanted to go live rock or base rock for my biological filtration. If you decide with base rock, I would get the rocks in and start curing it so by the time you are ready to put it in your tank they would have had time to build bacteria on it and it would give it time to leach out some of the phospates (which will help keep algae blooms to a minimum). If you decide LR, you will need to hold off on that until you get the tank running or if you have a holding bin for the LR, that will work. Other than that, I would start with the heart and viens of the tank (sump, return pump and plumbing).