You can order the water pipe kits from Samco iirc.
There is usually quite a long lead time on them, and most of the distributors seem to have to order them when you pay (rather than having them in stock, no matter what they say about having them).
You may get lucky and find that someone has the kit because they couldn't wait for the one they ordered to arrive and fitted one from someone else instead.
Last time I just bought some lengths of pipe that seemed to be suitable and replaced what I could... the rest I left, and crossed my fingers.
If the engine is out, I'd be tempted to change the DET sensor (I didn't when mine was out, but wish I had).