if you have 6 inboats, that amp from larry would be a good buy. if you are only running 4 inboats, I'd look for a 2ch amp not 4.
it would run tower speakers if you are only running a single pair but again if you want 4, I'd look for a 2ch.

if you like JL gear their m200/2 is only slightly more expensive new and would run 4 in boats. it's a little light in the power department for tower speakers.