the DP ecu offers a different map that is richer Air/Fuel mixture to compensate for the increased air flow.
For reflash you can get a Rexxer tuner and actually do it yourself. or send it a number of shops that do the same.
He says he already has bought a DP ecu. Guess he just wants to know the differance of the two.
I'd say the best air filter option you have with the DP ecu is the DP filter and airbox combo. The map was made for this filter. The other filters mention would probably require additional tuning.