I have never attempted an Achilles but one day I really want to, and this would be my ideal plan of action.
Flow: Since Achilles are naturally found in surge zones where the current is incredibly overpowering, in order to closly replicate their natural environment there should be so much flow that the only coral you will be able to keep are acros and the only other fish should be incredibly strong swimmers, i.e other large agressive tangs such as a clown or sohol. No gobies, blennies, or clownfish for this tank. I'm thinking 5-10 times more flow than you would find in the average reefers tank.
Diet: A varied diet consisting of calurpa (cultured naturally in a refugium), new era aegis pellets, new era marine grazers, larrys reef frenzy, larrys fish frenzy, larrys herbivore frenzy and new life spectrum pellets. Feed 2-4 times daily.
Tank Setup: I believe at least a 210 gallon is necessary to provide plenty of swimming room, lots of live rock for hiding/grazing, a UV sterilizer to help protect against ich and other parasitic infections, a refugium for nitrates, and GFO reactor for silicates and phosphates. Obviously there will be more equipment on this tank but these are a few things that many reefers overlook and I think is absolutely necessary for something as delicate as an Achilles. Maybe you can do without the GFO assuming your phosphates and silicates are in check.
Sound like a good plan? What do you other reefers think?