Just talked him into a Merlin for a tank.
I'd be reconsidering that Merlin. There's quite a extensive thread about Merlin and its unfixable seeping in here and the other forum. Bottom line is that the Merlin's base is pressfit and will eventually loosen from regular use and juice will seep all down your hitter. I tried to fix my merlins to no avail, my only solution is to have the Merlin sit on a mech with a solid pin so there is a space between the base of the merlin and the top of the mech.