Ranged is hard to play with in later stages of the game w/o BiS gear so make sure you have nice items
If you want to go Dw-ranged you can use the relic (Plunderer’s Talisman or any of the lower grade versions), the chest (Gunslinger’s Jacket and its Empowered version), the belt (Marauder’s Ammo Belt and its Empowered version) or the Barrelsmith guns. Your choice
To add on to what Chthon here just said, lifeleech isn’t exactly a damage type you build around. You have lifesteal (And your guns will innately have it IIRC, so you don’t even have to get devotions or the like for it, assuming you are going for the Cadence ranged build. Hard to tell, as both Cadence and Firestrike are viable ranged skills atm).
For enabling dual wield, I’d probably go with the Empowered Gunslinger Jacket. That passive bonus is pretty potent on it, and should make up for it’s lacking stats elsewhere at least.
For what you are going to focus (Assuming Cadence ranged focus), you will want things granting you flat physical damage ideally. Itemization would be anything granting + Cadence, + Deadly Momentum, and + Temper as a priority. Havoc and Deathdealer’s Sidearms cover the Cadence and Deadly Momentum side of things, Golemborne Greaves gives you some extra temper ranks, and after that you gotta fill in other places. There are some good phys helms, most notably the new Warborn set is dedicated to Cadence, and the helm would work well for the Cadence setup. It overlaps on the chestpiece though, so you would only be able to go 2 piece, or find another item to enable dual wield for the 3 piece bonus. Valdun’s hat is also a good choice (Valdun’s set is a physical/piece focused 2H ranged set, but a few of the items would work for dual wield fairly well).
Also, as far as build viability goes, you should be able to function well enough. While dual wield ranged is weaker for Cadence than 2H, it does have fair itemization at least, and Commando would be better than a Witchblade at it thanks to the extra source of flat physical damage in Temper.
-DW-Warborn Cadence Commando is pretty strong especially if you have that sweet new axe that drops in Valbury
-DW-Ranged Commando i am not sure how good ranged cadence actually is due to AS penalty being the highest for ranged weapons. You can build around fire strike as long as you know how to use the mines
-That Dreeg guy, have you reached max rep with all the factions yet?
-Late-game, imo any build can farm the end-game of GD as long as they have BiS gear. If you look at the recent builds posted here some of them use really whacky setups.
The problem lies in farming all that BiS gear. If i were you i’d probably make a 2h-Lightning Warder (High survivability) on SOFTCORE to farm the gear. Since you play HC imo you need BiS for your slots.