Hi,
The copper/nickel line kits are pretty good. I just fitted a set of pipes onto a TR4 and it installed well, bends a bit easier than steel lines. Do watch out for collapse on tighter bends. I ended up shortening some lines that were too long, not satisfied with the common practice of just coiling up extra tubing somewhere under the car. Not a big deal, though, and very easy to re-flare this tubing after it's shortened.
My one concern with copper/nickel is that it's relatively soft and might be more easily damaged by a stone thrown up from a tire, etc. So, I just used some 1/4" I.D. rubber hose to cover and protect the more exposed sections of the pipe. Most of the pipe is tucked well up in the frame or engine compartment, anyway, ouit of harm's way. Of course, it's necessary to remove and re-install the end to slip rubber hose onto the pipe.
The clutch master cylinder pipe was not included in the set, wish it was! I ended up just making up new one from a standard 3/16" steel pipe bought locally, reusing the ends off the old pipe.
Yes, it's really not hard to bend up your own pipes, if you are up for it. Just use the old ones as guides. Correct ends might be a little difficult to find.
www.fedhillusa.com seems to have many British-type fittings.
Another thing to watch is that the original fittings on many British cars use a "bubble", not a flare, on any "male" ends (i.e., at the master cylinders and the 3-, 4- and 5-way junctions). I don't know if this is the case with TR6, but it sure is with TR3 and 4. Put a flare on one of these fittings by mistake and it's pretty certain to leak.
P.S. Fed Hill also sells the copper/nickel 3/16" line by the foot. But, it's very expensive. Next time, I might try stainless steel pipe, although fittings might be impossible to get in S/S.
Cheers!
Alan