Know your stuff
Contemptor-Pattern Dreadnought (Forgeworld) - A more advanced dreadnought, with more weapons options, greater base strength, 13 12 10 armour, a weapon skill of 5 and a substantial points hike. Also comes with 'fleet' (VERY useful), and automatic shielding (5+ inv. against shooting, 6+ inv. against close combat, and +1" to explosion if it suffers a 'vehicle explodes' result). Adding an extra dreadnought CCW would be best to take full advantage of 'fleet', but a shooty dread may be good since at range it retains a 5+ inv. save, and because the Kheres Pattern assault cannon is murderlicious (it's an assault cannon that's assault fucking 6!). However, the better loadout is two dread CCW's (one of which may be a chainfist), because contemptors get access to some nifty built-in guns to their hands: there's your standard storm bolter and heavy flamer, plus a plasma blaster (assault 2 plasma gun with an 18" range) and the freaky-deaky graviton gun. This gat shoots an AP3 small blast that forces a strength test or die and makes the terrain it hit difficult; vehicles are auto-glanced. Oh, and you can give the contemptor BS5 to go with its WS5 for a small upgrade.
Contemptor Mortis (Forgeworld): Probably the best Contemptor variant, this guy trades in fleet for BS5 and AA shots if it stands still and can mount a big gun in each arm PLUS a cyclone missile launcher. Here's your loadout: ignore everything and take 2 Kheres pattern assault cannons and a cyclone missile launcher. There! You're done. If you find yourself not in range of the assault cannons, move forward and throw down with a couple of BS5 missiles. If you DO have something in assault cannon range, hold still and let the rape flow - your dread will loose a total of 12 S6 AP4 rending shots at 24" on a hapless unit and if you stood still, you can drop 2 more missiles on the poor fuckers ALL OF IT HITTING ON 2'S!
Contemptor Mortis (Forgeworld): Probably the best Contemptor variant, this guy trades in fleet for BS5 and AA shots if it stands still and can mount a big gun in each arm PLUS a cyclone missile launcher. Here's your loadout: ignore everything and take 2 Kheres pattern assault cannons and a cyclone missile launcher. There! You're done. If you find yourself not in range of the assault cannons, move forward and throw down with a couple of BS5 missiles. If you DO have something in assault cannon range, hold still and let the rape flow - your dread will loose a total of 12 S6 AP4 rending shots at 24" on a hapless unit and if you stood still, you can drop 2 more missiles on the poor fuckers ALL OF IT HITTING ON 2'S!