Use hollow braid polypro, and, as said above, run the line through the grommet, then pass the line through itself a couple of times to get the standoff you need from the grommets. The final "splice" is done by passing the line through itself a couple of times, then burying the bitter (loose) end inside the working line.
If you use three strand, I've seen a similar thing done, but passing the line under one strand a couple of times (best to choose different strands I think.) Final splice will be a regular 3-strand "braid back" splice (though I suppose a decent whip job would suffice as well.)
I've never seen the need for any kind of cover on the lifelines, but that's a matter of taste, I guess.