I would say, if you have the money,

1.) Get some cured live rock(30lbs or so), and ditch the limestone, or use it as a base rock
2.) Get a bakpak or a prism skimmer, and a powerhead or two for circulation

With the bakpak, you can keep your heater in it, and you can also drop a bag of carbon/phosphate sponge or what ever in it(this is what i am doing).