To Sump Or Not To Sump

[Palster]

Now that I have sold almost all of the Cichlids in my 135 gallon tank I am getting close to actually converting it over to salt water. The intent is to make this a predatory tank with a Trigger, Puffer, Lion and possibly a Tang etc. (basically messy eaters). The tank currently has two Aqua Clear 500 filters on it. I was wondering if it would be wise to drill the tank and install an over flow and sump when I tear it down or if the external power filters would be adequate as this will not be a reef tank. Does anyone have any thoughts? I already have a 50 gallon tank kicking around that is not in use that would make an ideal sump. The other option is to go with an overflow box instead of drilling.