Try this out for size- works out a couple points short of 1850.
HQ- Chapter Master in Terminator Armour (combi plas and chainfist)
Troop- 2x 10-man tactical Squad ( Plasma Gun + Heavy Bolter with Rhino)
Troop- 5-man scout squad (4x Sniper rifle, 1x Heavy Bolter)- in Landspeeder storm (with underslung Assaut Cannon)
Elite- Dreadnought- twin-linked Lascannon and Missile Launcher
Fast Attack- 2x Stormtalon gunships (2x Skyhammer missile launchers)
Heavy Support: Devastator Centurian squad(x3)1x Grav weapon +Grav amp, 2x Twin-linked lascannon
Heavy Support: Land Raider Redeemer + Multi Melta
Heavy Support: Stormraven Gunship: Twin linked Assault Cannon + Twin linked Multi Melta.
From what I can see, you have ample flying support, and a solid troop support for your big guns.
Forget about Calgar, basically a points sink with less perks than in 5th. Id rather run a chapter master and run him up with the centurians to pop a tank or two, or kill a high-profile target.
Id probably scout in the scout troop and transport, with the stormtalon escorting the craft onto the field to try and flank the enemy. Allow the LR to absorb alot of the damage, and unleash the centurians when within range. Use the tac squad to secure objectives, or take up firing positions and unload your firepower into them.
There may be issues if your flyers donnot make it onto the field by T3, but if youre lucky, and the enemy has limited flyers interceptors then could be quite useful.
I am aware there are some models you dont have at the moment, but with the models you currently have this is one particular loadup I would take.