Well my friend allow me to be the first to say welcome. There is no shame in picking an army that you like just based on the look of a particular unit (that is part of the reason I play DA) because what is the point of playing an army if you do not like it in some way and you are that much more motivated to build and paint those miniatures.
Going more into the subject at hand however, Ezekiel me and you are in the same boat with him and the others you named off, him and the vets are a nasty combo should you use it. Ezekiel has a relic that gives +1 attack to all DA units within 6" of him, so on a vet squad this can get scary because if you loadup your vets to be shoty and Ezekiel is in the squad its like they never lost their pistols and chainswords at all. This gets even better when they are built for melee as they are now 4 attacks per model defending and 5 attacks per model charging.
Ezekiel is a very good support character who can hold his own in a challenge as well so long as he does not fight anything ap2 as he only has 2+ and no invuln. If you want to make him a literal monster of attacks then you should be using him in a command squad (which are just vets so they have the same look but with command squad things like apothecaries, champions and banners.) Have him run with a command in a transport (preferably a landraider or razorback), chapter banner, then apothecary and champion are optional but are recommended. Finally have the big man himself use either interromancy or librarius. Librarius to make him more of a tank and crap on enemy psychers while buffing yourselff, and Interromancy to do basically the same thing with less buffs and more mind melting. Anyway hope to roll a 2 for interromancy or a 3 for librarius. This way the is walking around with 8 attacks on the charge.
More so into other character combos, as previously mentioned he does not have an invuln meaning someone like Azrael combos well because he gives him and his unti a 4++. Be warned though using the combos I have mentioned above all in one big death star (the command squad and Azrael) will be a BIG fire magnet so a raider is recommended or invisibility should you want to forefit some attacks for other psychic powers or have another librarian nearby give it to them.
Which brings me to my next point Librarians. Ezekiel is the OG for the Librarius conclave back in 6th edition and GW being GW took it and said lets give it to vanilla marines and the wolves. However our works differently it is him and 2-5 librarians the benefits is that we get the same 1 person knows the others powers but they can only cast on a 3+ instead of the vanilla marines 2+, also the primarus power in our Interromancy discipline has its range doubled to 24" so now you can blow peoples heads up from a safe distance and if they live they are that much more stupid.
As for an actual list that this would be effective in I would say shy way from formations as they do not support mass amounts of vets. But my recommendation would be take a Demi Company (or 2 if you want the free transports), then take scouts for a cheap auxiliary choice, take an Inner Cirlce of Azrael and then our Librarius Conclave and you should have the options to take everything you want. Be warned that again this does not support mass amounts of vets (only 1 squad of vets and command squad per demi company) but should you go with this you can always use the vets as hooded tac marines. As for taking actual vet squad however gear them up with combi weapons of your choosing and drop them in a pod 1st turn to kill what they need to. Also you now have full BS overwatch on everyone execpt the librarius conclave, they have BS 2 overwatch because of grim resolve which is our chapter tactic that gives BS2 overwatch and stubborn.
As an additional note before I end this Ravenwing and Deathwing would work well with this as well should you want to use either of their formations instead of a scout squad. Ravenwing being the more nasty of the 2 and Deathwing are a good pick as well but a little over priced and this is already an expensive list both in terms of points and money. But I highly recommend using the synergy of these wings along with the Greenwing.
I hope this helps my brother now go and make them repent.