Fellow Vets, I want to make a awesome tunnel rat vet build.

I would love to do a build that I have seen others in Havoc rock, they seem to spam Krak grenades like crazy. Like grenades for day type of crazy. Anyone got build recommendations? Games Latern has lots of choices but would love to hear from someone that has that build experience. I really want to run the Graia braced gun and I am open to suggestions on melee. To make it lore accurate, combat knife is very typical for the tunnel rats. Also would love to use infiltrate instead of voice since all my other vet builds use that and executioner stance. Lore would suggest that tunnel rats carry lots of breaching charges for their work, so Krak grenade is fitting imo. Any help would be appreciated...