You only really need to use braided hose instead of macroline if you are going to run it on CO2, and given the PMR will probably self destruct on CO2 you don't want to do that. The black stuff in the picture is macroline. You buy it in 12 inch lengths then cut it to the required length with a sharp knife and push it into the fittings.
If you've got a leak at either end you might get away with pulling the macroline out and putting it back in again, to pull it out hold the collar against the fitting and pull the hose. If that doesn't work and there is enough spare hose you could trim the end and put it back in.
Hope this helps.