You will need to buy the lower valance mate, they are around £200 from the dealers, then £90 for the lower black plastic, and £15 per reflector.
A Milltek backbox is around £450 new, or you can get a custom one made cheaper from a number of places.
The ED30 bumper will not allow you to fit the exhaust, unless you fancy some filling and plastic welding to move the gaps to the centre.