Bleed off pipes are the braided rubber pipes. yep go between the injectors and one links back to the pump.
Not sure on the 200 and std injectors but don't see why not, just have to measure and make sure they are the same size and won't hit anything.
The washers are copper ones that crush up and fit on the injectors to seal them I get them from a land rover parts place or that DMGRS place has them.
https://www.dmgrs.co.uk
think you can get them ultra sound cleaned, don't know the price. I keep away from cleaning them so I don't block anything up!!