A kill team of nothing but stealths breaks too many rules for my liking, but having a couple is really useful.
I've used a team of two stealths and some fire warriors with carbines with decent results (this was pre-TE, so I haven't used my updated team yet, but it's basically the same... but with TAs, and Ethereal Bodyguard; yay for Bs4). I used Camo Gear; shoot, wait, shoot, wait. It usually works fairly well.
...The other option is to do the sniper thing. All Rifles with maybe a Rail Rifle for fun. Sit as far away as possible and peg off the Brutes one at a time. (again, Camo gear would be great for this).
Kill Team is fun. Especially when you play an even number of times, alternating KT and brutes. Do what you think would be fun.