You can get all the fittings from Supercheap - aluminium and silicone pipe, 3" - 76mm is what you'll need, filter sizes are measured from the inside the connection.
A 3" filter connection by 5" width and 6" length is what I managed to fit in behind the fog light and wheel well.
Here's a pic of mine
You'll need to mount the end of the induction pipe to the chassis or pipe it through a alloy plate as I've done or else vibration will be felt through the car when you plant ya foot, it'll help block heat as well.