Bought some silicon tubes from eBay and dad got hold of some stainless pipe for the water plumbing. Originally we were going to bend the pipe but had a quick look on eBay and the silicon tubes were cheap enough so went for them instead. We're going to fasten the pipes onto the chassis with a couple of clips later to give them some support.
We realised we had bodged up a bit with where we mounted the engine because when we made the mounts we didn't have the thermostat housing on! So when we tried to put it back on later with the engine mounted, it wouldn't fit because it is too close to the chassis D'oh! Dad made this one instead which is a bit of a mix and match of pieces but should do the job nicely.
Bought this header tank from eBay too £35 its really nice and is perfect for what we need. Going to get some silicon tubes to get this plumbed in as well.