If its straight lengths, - for eaxmple a big motor factor in Milton Keynes sells 1mtr lenths of approx 38mm (and other sizes) for around 18 quid (!!!)
If its bendy bits, Halfords do spiral flexy lenghts in various sizes for about a tenner a chuck. I have two 35mm dia 400mm spiral thingys on my car.
If its fixed bends, id suggest you beg or borrow a veneer caliper and measure the sizes you need, then get to a scrappy and find something there.
For example, botom hose from a sierra is about 20 quid at a factors, 1 quid at a scrappy.
You can at least find if it fits, and if you want to buy new, you know what to go for.
Do bear in mind any hoses to heaters inside the car need to be installed with great care - we all learnt this from Hicosts recent bad event.
atb
steve