4 large lasers, AC-20, and the heatsinks to use them... kinda. Should be a pretty nasty build to run into at mid range. It really depends on what the laser hardpoints are like in the right torso. If they are grouped pretty close to each other, then this build is like a Griffon-S on crack. If they are spread out, though, its back to the drawing board. EDIT 3/19 Finally got my 3S and took this build out for a spin and it wrecks faces pretty damn hard. I had to make a couple of changes to make it work though. First and foremost is the inclusion of the OP Aiden Pryde Small Laser Of Doom. Why? The first non-ppc laser placed in the RT will automatically be placed in the hip location. Each laser after that is put in the 4-slot, 0-convergence location in the upper right torso. What does this mean? The 4 large lasers end up like this... Heat is a problem, but is generally manageable by splitting the lasers into two firing groups of two (and I am not counting the SL since it has retired to Fiji, where it basks in its own awesomeness). Even at basic mech skills, you can get 2-3 alpha strikes before shutting down. That is usually enough to lop off good sized chunks of most mechs. If you end up overdoing it, you can fall back on the AC-20 for a little bit to cool off.
4 LL on their own are hot enough lol, also imo you are kinda missing the selling point of the banshee which is speed. I for one will be running meta-fag builds like this one: Good overall damage, speed, armor, and heat efficiency. I run a similar build on my victor but with a massive xl for extra a$$holishness. If you really want ll and a large ballistic i would run this: