i've been using thermal ink occasionally with the heavy, but i've been using the shoes from my non-thermal ink build. i wanted a build with ink res and bomb defense too, so i finally made it.
note that i've only tagged the og heavy and the remix, because i prefer to put special power up on weapons with bubble blowers. i also don't use the deco. like, at all.
run speed: every splatling needs run speed in order to be more mobile while charging and shooting. also really nice for running over grates like in kelp dome.
thermal ink: the heavy has great range and can be good at getting fall-off damage on someone, allowing you to then track them. it's also useful to keep track of opponents as a backliner, because sometimes they'll retreat after being shot and then try to flank.
ink saver main: i mean, it's kind of an ink-hungry weapon...
qsj: honestly? most people use this to jump back in quickly after dying, but i use it to jump back to spawn. a backliner should stay alive, ESPECIALLY one with stingray. just one sub of qsj often means the difference between living or dying.
bomb defense DX: people will often toss bombs at backliners or try to kill you with inkjet. this helps you survive.
ink res: i'll step in enemy ink while charging pretty often. it's annoying.