Stocking suggestions for 60P with RCS

I had an ammonia spike suddenly kill off 5 of my 9 harlequin rasbora recently. Not a fun day, but it happens. The tank is now back to normal parameters, and my girlfriend wants to try another species of fish this time around. I need something that will be ok with the 4 remaining harlequins and ideally won't eat too many baby RCS (an occasional cull is fine with me... only the strong survive!).

So far I am thinking some corydoras habrosus, some less-nippy variety of tetra, or ...?

Suggestions?

Mr. Aqua 17.7, Eco Complete with DHG, blyxa, various stems, and seiryu stone
Pressurized CO2
Eheim 2232
pH 7.6
KH/GH 8
Temp 76F (but can adjust +/- around 5 degrees)