Hi Everyone

I have a 2002 A6 Avant 2.5 TDI and the offside bank of injectors (or maybe return hoses?) appear to be leaking. Has been like this for some time but now getting lumpy ride. Recently had the AA out to start car (air in fuel line).
I'm planning to replace the braided fuel return hoses and remove and clean the injectors.
I have a few questions:

1) I've found braided fuel hose online, can I cut sections to fit or do I need to buy the complete length with all sections and connectors already assembled?
2) The workshop manual recommends replacing the seals on the return hoses but I cannot find these anywhere, I think they're just washers according to the diagram. Any ideas would be very welcome.
3) Any advice on cleaning injectors and the injector seating would also be really appreciated.

I had asked a garage about the injector cleaning and replacing and they can do this, but it's a lengthy job and labour time makes it cost-prohibitive. So rather than scrapping my car that I've had since 2002 and has been running really well I'm going to have a crack at this myself.

Any advice and help would be greatly appreciated.

Thanks