Tossing up between an Imperial Knight, Land Raider, or those (repulsors, repulsor executioners, and the other one I am forgetting). Most of my army is primaris, however I do have a strong element of Deathwing in them. What choice would be a good fit for an army? (In an optimised scenario)

Reasons for why I want <insert vehicle here>

1.Imperial Knight - mostly for the badass element, seeing a lot of guns, so I imagine it does a LOT of damage, especially if it has plasma weapons.

1. Land Raider - still respectable damage from what I read, (if not super-seeded by the newer vehicles) mostly for transporting my Deathwing. 

2. Primaris vehicles - because the army is mostly consisted of primaris dark angels. 

EDIT: As for not why the ravenwing, don't have any ravenwing elements in my army as off yet, it is something I need to work on admittedly. 

For reference, my current army:

-1 Primaris Captain in Gravis Armor

-2 Primaris Lieutenants

-1 Primaris Company Ancient 

-1 Kitbashed Primaris Apothecary 

-3 Primaris Intercessor Squads of 5

-1 Primaris Hellblaster Squad of 5

-1 Deathwing Knights Squad of 5

-1 Deathwing Squad (storm bolter/missile launcher combo) of 5

-1 Primaris Inceptor Squad of 3

-1 Primaris Reiver Squad of 3