Oi, where should I begin.

Weapon: Rotary Canon.
Mods: damage, damage+ammo, damage+aoe
Elite ranks: weapon AoE to the max, a bit into range.
Justification: With those mods and 70 elite ranks into weapon AoE the Rotary Canon might as well be renamed into a Rotary Grenade Launcher. 100m range is good, but just a bit lacking to get some of the more distant mobs.


View:




Abilities
Thunderdome, Heavy Armor, Turret Mode, Dreadfield.
Mod everything into cooldown first. Rotate Thunderdome and Heavy armor to stay invincible 95% of the time and facetank Juggernauts in Turret Mode, where the debuff from Dreadfield becomes useful.
Obtain a set of Transcendent prefixed abilities (cdr + pr), and armor with prefixes that provides Ability Cooldown reduction. Tinker the crap out of your reactor for extra PR.
VMBx8 OS is nice.

Perks
You'll likely need some extra perk points to fit the good ones.



You need at least 42k health to comfortably survive two sniper shots in DoD. Get it with perks, via tinkering armor, or using armor with bonus health.
Health surge is nice since you're popping abilities all the time. Turret mode procs it on both entering and exiting the mode. Not sure whether the effect stacks when doing that quickly.
My gun does kinetic damage which has damage boosting perks.
The usual Kill Stealer, Necrotic Bite, Chosen Hunter and Anatomy lessons to up the damage on what hurts you the most.
A bit of speed.
Lastly, and most importantly - Quick Flexing Servos a.k.a godmode for dreads. Jumping around like a headless chicken screws up AI targeting (especially those grenade lobbing Chosen) and since it doesn't use jet energy, you can save it up for when you need it.

Elite Ranks


Something like that.

Tips
Never use Thunderdome if you are in front of someone. Better die than incur the karma penalty for blocking everyone else's shots. If you have to, quickly move out of the way.
Heavy armor is seriously OP with some duration and potency invested via Elite Ranks. Forward shield it provides is invulnerable. Use it to facetank Juggernaut beams, Ultratroopers, Chaingunners, Armored scorchers in Miru HC and whatnot.
Always keep either Thunderdome or Heavy Armor on cooldown for emergencies: getting way over your head, or needing to revive someone. Rotate them out normally to stay invincible.
Use Dreadfield to debuff tough targets while facetanking them. The range is not there to use it elsewhere, so just save it up for the occasion.
Use Turret mode for proccing Health Surge by quickly entering and exiting the mode.
Use Turret mode while facetanking with heavy armor. You're invulnerable anyway, and the extra 30-40% DPS with the gun's huge AoE wouldn't hurt.
Get the Automated Medical Circuit gadget. You'll be too busy jumping around and shooting things to manually activate your medical system.
Get the medical system with the -10s cooldown bonus.

Just an update.
Ever since gaining some more elite ranks an getting an over 100% damage reduction effect on heavy armor I've switched away from focusing on tank into focusing on mobility.
Charge took place of Thunderdome, and I'm currently running with a full set of Explorer's gear (+speed) and the following perks, managing a 10.37 m/sec.


Instead of Thunderdome I simply Charge away when under fire and with Heavy Armor on cooldown. Unlike Thunderdome however, Charge is also good for generally moving around.