Either go big with the high mounted guns or avoid them entirely. A pure Ebon Jag B, if you mount only one energy weapon in the left torso has no "bunny ear" to shoot off. Because one high mounted gun isn't going to do anything except draw fire. But if you field it with a right torso from a -D and a left torso from an -A, then you have THREE high mounts, and you can do a lot more with those high mounted guns.
Running a pure -B with a left torso from an -A gives you one bunny ear with two high mounts and keeps the ERPPC heat quirk, allowing you to have two high mounted ERPPCs backed by six ERML low mounted and stuff it full of heat sinks.