Best place to start is will stage 1 mapping and getting the car to run correct at this stage, once you know your running good stage1 power, you can then compliment the map by adding your bolt on goodies, exhaust, induction kit, fmic, tip and then ko3s then get a custom map to make the most of your mods and turbo.
As for the dump valve, as long as it's not leaking or bleeding boost off it should be fine. If it's a blow off dump valve you should fine fine still on the agu, you will get fuel trim issues because the air is being vented but the ecu can account for this to an extent.
A healthy running mapped ko3 @ 190bhp/225lbft should give you a big grin and transform your car.