Guy up here (Ottawa) did a whole army like you are talking about.
With time and effort the army can look amazing. He's won several best painted awards in Tournaments/Grand Tournaments.
He even placed exceptionally high in Bell of lost Souls design your own regiment contest. His were the Golgothan Brotherhood.
Essentially he used Dwarf bodies, Cadian arms, backpacks i think from the Cadian sprues, added searchlights to all their shoulders...and then greenstuffed visors on to them all, looked pretty sweet
He also did Exo-suits counting as Ogryns, made from terminators and heavilly coverted (think lowered,
lol), and he modified his tanks to be all low profile.
Essentially for the tanks he removed the turrets and hull mounted all the weapons, then added a tonne of Dwarfish iconography.
And thats not even mentioning the tirkes he did for his Rough Riders, or the mole mortars, or the rapiers as autocannons, etc, etc...
Take some time, play with the sprues a bit, the army is a great oppurtunity to show off modelling skills (trust me, it takes a tonne of conversions and $$ to make the army look nice )