Yes, A calcium reactor is just an easier way of meeting the supply and demand on your tank for alk/ca levels. You can mantain CA many ways a reactor the simplist. Kalk will do just as good, look at Sue Truetts tanks I believe she does it with kalk only.
Lighting on this tank for acropora IMO should be 3 400 watt MH 6500k with 2-4 160 watt VHO actinics.
