Knight is lightyears ahead of the Dreadnought. Our 'noughts are more expensive than any other faction because of the psychic powers that they really don't need. Always make sure the DK has a teleporter. I prefer the sword for master-crafted, some like hammer for concussion. Incinerator is great. Psycannon is gravy.I've just started playing GK and noticed my lack of heavy firing ability in my first couple of matches (Tau, Skitarri), I remedied this by added the Vindicare and the dreadnought with plasma for anti-tank. Also packing a decent number of psycannonys. Im considering getting another Dreadknight (to replace the strike squad or dreadnought) could i get a comparison between the knight and nought
If you really want Dreadnoughts, I highly recommend allying in Space Wolves. It's not fluffy at all, but their Champions of the Great Wolf detachment requires 1 HQ and 2 Elites. Their dreadnoughts are cheaper, can also take plasma cannons, autocannons, even helfrost if you wanted. Heck, if you really wanted, you could take 2 Elites and Bjorn as your HQ, adding 3 dreadnoughts to the list.
You never really want to give Strikes psycannons, because of the Salvo rule. They're just plain bad on a Power Armor frame. it's why Terminators are the super troop choice now, especially fore firepower.
My recommendation would be a Stormraven, definitely. Meltas and Lascannons for anti-tank. Split the terminators up, let one hide inside if you want, or the interceptors.