I'm running duals from DC Power and the MLA. I recommend you get the biggest alt that Robbie say's you can run in your car along with an MLA and back it up with as big of a battery bank as u can fit. The MLA is the smarter route to go then the external regulator because the MLA bypass's your charging voltage but not the alt censoring. So if you were to overdrive your alt and it started getting too hot, it would still normally shut itself off.3
And $449, if it's for a DC alt? its worth it!!