Dirty custom Sunspider.
Sight line and weapons are perfect for peeking and tagging. HMGs are great for defense if people think they can abuse ATMs min. range. Kills the fuck out of lights too.
Ghost heat penalty is minimal, worth the heat/tonnage to use an ATM12 instead of a third ATM9.

Vapor Eagle may be the best poptart but this feels great for regular ATM play.