I'll have the same problem when my 25 year old hoses start to give up. For the hoses I'm sure replacements of the correct diameter will bend to the correct shape well enough. If there are any really tight corners then 90 degree "elbows" can be found.
For the adapters into the waterpump it's "hose ends" you'll need to search for, together with the thread type. I'm not sure which thread they use. Most likely an unusual metric fine thread rather than the similar BSP one.
There will be a lot of this going on in the future. The bits Renault used were cheaper for mass production, but when they fall out of production there are plenty of ways of making up the bits from generic parts.