Simple Question!

I have a more or less nearly new standard MY12 VRS CR170 with no Sat Nav, BT, Maxidot or MDI.

Do I:-

1) Build up my car using VAG parts, Columbus, BT Kit, MDI Kit, etc or

2) Buy a Kenwood DNX-520VBT.

I accept that I will use some interface functionality on the climate control settings but what should I do, need to make a decision soon as I need my phone for business use.

I have had some great advice so far from fellow members but the costs are rising and I can get the Kenwood for £595 all in.