kribs are a nice fish to breed its often hard to get them to stop breeding
anothergroup of fish you may like to try are corys (Corydoras)
they are small peacefull catfish
with those lights it wont be good enough for marine.
as a basic rule i would say about a watt per L of water
also depends on what type of coral
things like zoas and mushies dont need strong light but sps corals will need alot stronger