If you are still looking then melun Auto have a promotion on R4 hoses at the moment at https://www.melun-retro-passion.com/ It's on their opening page , left hand side.
It's easy to order the wrong bottom hose by mistake. The one for LHD cars is widely available from the usual websites and on eBay. The RHD hose is a different shape - it has to be to clear the steering column, and is almost impossible to find new. The secondhand option sounds good!
LHD bottom hose on the left; RHD on the right.