Welcome to Librarium Online!
I play imperial guard and am frustrated with the weakness of the units, but i don't like the bulky SM armies, i'm trying to develop a middle ground between them, an army that i won't have over armored guys but won't need 50 IG models. any ideas or suggestions?
Well, of course theres the Inquisitors. They have some Grey Knights but they're not really HUGE HUGE.
Imperial Guard grenadiers.. or stormtrooper heavy Inquisitor armies (which can also be used to represent arbites.)
Or better still, sisters of battle.
If you want to throw together a house rule army, make sure it's not too much like any of these.