So ran this a few weeks ago and did pretty well in a tournament. I built the list using Battlescribe and was originally trying to run 4 suits, then decided against it because I'd only lose 2 models for break checks to start happening, but I forgot to change the codex in Battlescribe so it gave all my models bonding knives which ate up points that I could've used for another fire warrior or burst cannon.
Airbursting Fragmentation Launcher
Twin linked Plasma Rifle
Twin linked Missile Pod
Total of 199 points.
Pretty simple and straightforward....
-Give the ignore cover trait to the plasma suit to eat up power armor.
-Give feel no pain to the AFL / flamer suit. Use him as the template guy. Primarily firing off the AFL, the jet packing out of line of sight if possible. Flamer is there to discourage assaults and give him automatic over watch hits. FNP gives him extra protection since he'll likely be in range of most or your opponents guns.
-Missile suit / leader uses his range to pick off dudes across the board while sitting in his corner of safety (aka take out enemy specialists or leader)
-1 of the fire warriors usually ends up getting the 3rd specialist trait. Trait choice is usually a toss up between preferred enemy and stealth.