This is my classified version of Topper Harley Lonestar Ninja (named after Hot Shots Part Deux's scene). You've got piles of ammunition and seekers to make sure NPC's are not in cover (to take full advantage of your LMG's passive damage buff). Twin MG5's ensure that you are dishing out damage, healing constantly (Lonestar's big weakness I think) and getting your skills back really quickly. An alternative to Seekers is flashbang, both will lift NPC’s out of cover for you to take down. If you work fast, flashbang is better to catch the NPC’s when they spawn.
If you have Big Alejandro, you could use those instead, but then you lose out on Determined in the free slot on both weapons. I’ve tried Destructive and Predatory in both Big Al’s. But, I lose out the ability to farm back any skills, including my signature. It’s really a preference thing. Solo I’d probably go MG5’s and in a team Big Al.