Any CT energy variant will do. Name comes from the fact that asides from legs and head, only uses the Right Torso from a -D. I actually enjoy this build a fair bit, I run the arm lasers as a weapon group (and a second one chainfired), the torso lasers as a weapon group and the SRM's by themselves. I do primarily use the torso lasers first unless I'm at close to base heat, in which case use all the lasers. Splat is for when you get close, or something gets close to you, it's a nice supplement to decent firepower. And it's sustainable to keep pushing damage when you're riding redline.
_ Tuned for a cooler version. Group 1 - 2x HLL, 5x ERML Group 2 - 2x SRM6, 1x MPL Group 3 - Arms Group 4 - Medium Lasers chain fire Group 5 - High Laser poke (add or remove ERML as you want) So you Group 1 loses one ERML, but becomes much easier to use on neutral and hot maps. Alpha is the same at short ranges. Use Group 2 for short range sustained engagements. More damage, more spread of missiles. MPL is much better than ERML for efficiency and burn duration. On Caustic, even with an extra heat sink and skills, you are pushing 100% heat with an apha (especially if moving).
There's an interesting alt. I like it, Artemis isn't overly expensive so I'll give that a try and see how I feel about it. I could also suggest swapping the HLL for ERLL, keeping the CT ERML and adding yet another DHS to the Left Torso, for heat and I suppose more range flexibility with the high mounted lasers.
All about that heat. The clans are all hot and bothered for super rapid knife brawls and fast engagements (kind of necessitating that their weapons generate the same or less heat than Star League era stuff) but in this PGI-defined battletech world clan shit just means extra duration, extra cool down and extra heat for sometimes more damage and usually more range. (Also generally smaller and/or weighs a bit less)
