IMO 2.5 - 3.5 Meq/L balanced with Ca levels of 420 - 460.
ie..
I consider the following to be balanced levels:
Alk 2.5 Meq/L - Ca 420ppm
Alk 3.0 Meq/L - Ca 440ppm
Alk 3.5 Meq/L - Ca 460ppm
My coral selection is about the same as yours.... I keep alk around 2.8-3.5 meg/l & calcium around 450 ppm...with a steady ph of 8.0-8.3....works well for me!