Hmm....
I thought about it in terms of 6 packs with 2 "bonus" figs
Ok to start I'd like to do:
Grunt V1: PoC Dusty Head (new coloring) PoC Dusty Helmet, Goggles, SE54 Body, Resolute Stalker Vest, Grunt V1 Backpack retooled, SCAR rifle, basically just like the great customs we've seen but in US multicam camo

Lt. Falcon: BBTS Head & beret (in Green!), Recondo Torso, PoC Duke Desert Battle Arms, SE54 Upper Legs, Duke desert battle lower legs, resolute Flint Vest, Falcon Backpack,radio & Knife, Resolute Flint Shotgun Shell Wrist Guard, pistol with silencer, Spas 12 and SCAR rifle. in tiger stripe.
Joe Colton: (The Old Man) Something like Slayer's Male Head 183, Desert Battle Snake Eyes torso, arms, jacket, Duke Desert Battle legs. Twin Mac-10s, Lifeline's Tactical M4 rifle
Mayday: New Head, Agent Helix Torso, RoC Baroness Arms, Lady Jay 2009 pack Legs, PoC Lowlight's rifle, case, spotter scope, Baroness MP7 submachine gun. In multicam
Ghost Rider: Head: 30th Anniv Duke new colors, Capt Ace's Helmet and body in Grays and Black, red cloth scarf, 45 pistol for ankle holster.
Repeater: TRU RoC Troop Builder MP head, PoC Dusty Torso and Arms, Duke Desert Battle Legs, PoC Iron Grenadier Steady-Cam Gun. In Multicam
T.A.R.G.A.T.: New Helmet, Cobra Diver head, Arctic Threat Destro Torso & upper arms, Skydive Lower Arms & Vest, Jet Pack, Capt Ace Legs, Iron Grenadier Pistol Shock Trooper Rifle. In classic TARGAT Colors.
Iron Grenadier Trooper: IG Trooper Head, Shock Trooper Torso & Upper arms & Vest, PoC Firefly lower arms and legs, Poc Firefly Rifle painted in urban combat camo, grays & blacks
Voltar: New Helmet, Clutch Head, Battle Armor CC Torso, IG Destro Arms and Legs, IG laser Pistol Destro Sword, Vulture. Should be in black and Gold.
Mistress Armada: New Head (although RoC Training Scarlett's head with new colors could work) Agent Helix Torso & Upper legs, Baroness V16 Arms & Lower Legs, Resolute Baroness' twin machine pistols, comic pack firefly goggles. In IG Black
Undertow: Cobra Diver Head, Torpedo Body, RoC Shipwreck Dive Gear & Spear Gun, silenced pistol, kinfe, baracuda. In Urban Camo Gray, black and red.
Iron Grenadier Sgt Major: Sgt Stone Head (Red Beret), shock trooper torso & Vest, range viper arms and legs, IG Sword, PoC Firefly Rifle
Bonus:
Horror Show: New Helmet, Bazooka Head &Torso, New Vest Updating his coat to PoC Style, PoC Snow Job arms,PoC Destro V26 Legs, RPG, Snow Serpent AKM. In Classic Horror Show colors.
Daina: New Fur Hat, Helix Head, Lady Jay 2009 Torso (no high collar), Helix Arms, Lady Jay Legs, Dragunov Rifle. Classic Daina color
I kind of fell into the Iron Grenadier theme. I wanted a Targat, and I realized that the IGs hadn't been fleshed out in the modern line so I tired here.
Also the SE54 body is great for any of the original 13 guys.