Hmm no replies yet? I guess i'll be the first. Welcome to the SW side.
That seems like a lot of rock for a 10gal, guess it depends on each pieces size and shape.
I'd go with the 80w personally. I think you'll like it in the long run, opening your choices of coral even if they are softies. Also more light can mean a difference of having to place the frags high on rock, or on the bottom of the tank. Just more flexibility.
As far as test kits, i know you can use the High Range pH test, not sure about the others. High range pH for sure.