Hm-mm-mh.

Go with a 2 speed and a non-electronic time clock. Do NOT spend money on an electronic control system!

Also be VERY sure that all the bonding and grounding is done meticulously. You'll want to have all those ducks in a row BEFORE they start putting steel and rebar in the ground. It's easy, and not too expensive, to do all that right IF you get everything ready BEFORE any concrete is poured or any gunite shot. I can tell you what to look for, after you have a pool design.