I saw a comment about "stealth LRM Elemental" in the Elemental BAotW so figured, why not?
Take an Elemental, swap the armor to Improved Stealth, swap the missile pack to LRM-2 with 4 shots. This reduces the modular weapon mount capacity to one slot and 75kg, meaning the only weapon options are a light machine gun or a light TAG. (Or it might not have a modular weapon mount at all, not sure since i did this with MML and didn't double check things by hand. But ultimately it is irrelevant.)
It may not be as dangerous as the standard Elemental (or Elemental [Fire]) but sure is annoying. It is hard to hit, reasonably mobile LRM-10 battery after all.
Elemental Battle Armor [LRM-Stealth-LMG]
Clan TW
BV: 475
Cost: 4,027,900 C-bills
Movement: 1/1/3
Internal: 5
Armor: 50
Internal Armor
--------------------------------------
Trooper 1 1 10
Trooper 2 1 10
Trooper 3 1 10
Trooper 4 1 10
Trooper 5 1 10
Weapon Loc Heat
----------------------------------------
Auto-Rifle (Left arm) (APM) Point 0
Swarm Mek Point 0
Attack Swarmed Mek Point 0
Stop Swarm Attack Point 0
Leg Attack Point 0
Light Machine Gun (Right arm) Point 0
LRM 2 (Body) Point 0
Ammo Loc Shots
----------------------------------------
BA LRM 2 Ammo Point 4
Equipment Loc
----------------------------------
Anti Personnel Weapon Mount (Left arm) Point
Battle Claw (Left arm) Point
BA Stealth (Improved) (Left arm) Point
BA Stealth (Improved) (Body) Point
BA Stealth (Improved) (Right arm) Point
BA Stealth (Improved) (Right arm) Point
BA Stealth (Improved) (Left arm) Point
Elemental Battle Armor [LRM-Stealth-TAG]
Clan TW
BV: 421
Cost: 4,202,900 C-bills
Movement: 1/1/3
Internal: 5
Armor: 50
Internal Armor
--------------------------------------
Trooper 1 1 10
Trooper 2 1 10
Trooper 3 1 10
Trooper 4 1 10
Trooper 5 1 10
Weapon Loc Heat
----------------------------------------
Auto-Rifle (Left arm) (APM) Point 0
Swarm Mek Point 0
Attack Swarmed Mek Point 0
Stop Swarm Attack Point 0
Leg Attack Point 0
LRM 2 (Body) Point 0
Light TAG (Right arm) Point 0
Ammo Loc Shots
----------------------------------------
BA LRM 2 Ammo Point 4
Equipment Loc
----------------------------------
Anti Personnel Weapon Mount (Left arm) Point
Battle Claw (Left arm) Point
BA Stealth (Improved) (Left arm) Point
BA Stealth (Improved) (Body) Point
BA Stealth (Improved) (Right arm) Point
BA Stealth (Improved) (Right arm) Point
BA Stealth (Improved) (Left arm) Point