Black neon tetras cope with hard water well - in fact, I suspect one of mine is actually a piranha in disguise because its so enormous for a black neon!
It's thriving in pH 8.2.
Danios are great in a 30 gal tank and can cope with anything you throw at them.
Siamese Algae Eaters are great in hard water but do make sure you actually get SAEs and not another species - some species don't eat algae but more importantly, aren't shoaling community fish like SAEs. A single Flying Fox would be a similar alternative (but territorial so you need to be careful what you have with it).
Gold or cherry barbs cope well and can be kept in a small group (male plus a harem of females).
Platties and swordtails can cope well. Mollies are great with guppies but might reduce your choices of other fish, due to their territorial nature.
Pearl and dwarf gouramis are both pretty tolerant of water conditions.
White cloud mountain minnows are fine with anything, but do take up the same upper swimming level as guppies.
In fact, its probably easier to tell you what isn't compatible - I know people around here who even succeed with breeding angelfish and corys in our high pH! The important thing is to get locally raised fish who are used to the conditions.
I would strongly recommend some bogwood for hard, alkaline water because it will gradually soften your water and slowly drop your pH a few points (my "Amazon" tank is at pH 6.8, from our tap water at pH 8.2-8.8, thanks largely to bogwood). You could also consider pre-filtering through peat, which is a simple technique that can have tremendous positive effects.