In my opinion the best way to go would be to add a bunch more rock and get that skimmer then ditching the filters. The majority of the beneficial bacteria reside on the rock, so the more you have the stronger your system is for breaking down ammonia and nitrites. The skimmer is a no brainer too, thats always gonna be a help for any tank. lol
But if you have other plans, then I would say look into the fluval canisters, I ran a fluval 305 on my 55g for awhile and it worked very well. The only caveat would be is that you really really have to be on your water changes and cleaning the canister as the nitrate buildup can get crazy.