I have yet to get an amplifier for my antenna, but I did get a distribution amp (powered splitter). Made a world of difference. Signal boost was 20% for all my stations and it allowed for me to grab an extra station just barely.
So I am going to get up there, readjust my antenna I think 15degrees and add a antenna amp. Should end up getting all my 11 stations / 30channels in the 90%+ range.
DirectTV lines have a ground on them, so you won't have to worry about that. Just check the ground on both ends and make sure they are at least connected.
I was going to use my DirecTV lines but discovered the last provider I used when they ran their "own" coax, they snipped the feed from the dish in multiple places.
So when I get up there I now need to run a ground as well.