Hi,

If the suction lines are in fact 1.5" I would go with a full rated 3/4HP or an uprated 1HP. It will turn over your water in about 7 hours a day. And since you are using a Polaris cleaner with a booster pump you will be fine. I'm not a fan of 2 speed pumps..... the gpm drops to next to nothing at around 21ft of head.

I definately would not do a 2 hp because of the plumbing sizes.