For SPS, I would be trying to get my ALK up to 9 KH slowly. Rapid swings (Alk, temp, etc.) can lead to recession. Once you get ALK up where you want it, then you can dose with whatever works for you and your tank to maintain Ca and ALK. Personally, I think daily dosing with a balanced two part is best (safest) for small tanks, if needed. KALK disasters are not unheard of even on big tanks.
Since your pH is low you could use Seachem Reef Buffer to raise both ALK and pH. Your calcium is fine to slightly high IMO. I shoot for 450.