preferably PTFE so it doesn't dissolve in brake fluid.

And needs to be quite tough as use a vacuum bleeder (buy one, they really are a revelation if you have more than one set of brakes to bleed, took literally seconds to do some hope minis).

Problem is shimano use tiny nipples so I need some ~3mm ID tube.

Local DIY store. Most have a range – even B&Q carry it.

B&Q/Homebase sell hose by the meter.

Just chop off the length you want, and you're sorted.

I always get mine from there – Wide diameter for Hope, narrow for Shimano.

Simples : )

Where did you get the vaccum bleed kit? what sort is it? quite like the idea of one

This one for £40 on ebay

I'm sure I didn't pay that much, but it does make the whole job easier, just buy some plumbers/PTFE tape to warp around the thread on the nipple to create a good seal otherwise you just suck air through the threads.

Makes it easier to do bigger jobs like the car brakes but doing the bike brakes is a piece of piss too, just remember to keep topping up the reservoir, and give the lever a squeeze every so often to make sure there's no air in the master cylinder.

Looking at it critically I'd get something that was self supporting, so could be stood on the floor/worktop while you do things, that one I linked to can take two hands just to hold it!

dunno how tough or what size it is but I used windscreen washer fluid tubing from halfords for bleeding my hopes