JSabah,
I don't know about the difference between the two brands, but you can get ahold of the factory reps and discuss the what the differences might be. Here is an interesting article on the background of the copper nickel lines:
https://www.copper.org/applications/automotive/brake-tube/brake.html
Note that the copper nickel lines have the same ultimate strength as the steel. The yield is lower though. The main reason for going to the CuNi lines though is for corrosion issues. SS lines are very nice too, but can only withstand a single 37 degree single flare, so require all new fittings and new tools if you plan on modifying the system. Many of the SS installations also incorporate aluminum fittings, which introduce corrosion issues in themselves, so if you can install the SS system with all SS or steel fittings, then that system would be fine also. Note also that aluminum brake fittings are no longer allowed in sanctioned racing events (from talking with some racers in the pits at PIR last year - I have no other background on that issue).
I installed a NiCu kit from Almec in the UK in my BJ8, and am very happy with the results. It came with all new brass fittings which was the reason I went with them. I had only one problem with the kit, the line to the remote reservoir was too short, and they promptly sent me a replacement at no cost.
Good luck with your install......