That's quite a good report, it has almost everything the aquarist needs to know. [The main things missing are ammonia,nitrite and nitrate, all of which may be present though fortunately not usually, but you can test the tap water for these with our aquarium test kits.]
You have soft water, so forget livebearers. The total hardness at an average of 109 ppm (= 6 dGH) is much too soft. You are ideally suited to soft water fish.
As for the pH, the Alkalinity (this is the carbonate hardness) at average 66 ppm (= 3-4 dKH) is not going to buffer pH very much, so my suggestion here would be to dilute the initial aquarium water with pure water (distilled, or clean rainwater works even better). This will stabilize things, and future water changes will be safe. But it would also be good to find out if the water authority is adding something to raise the pH. I would suspect this as so high a pH with so low a GH/KH is unlikely in natural waters, though not unheard of.