Ken,
I have the EoTech 557 on one of my AR's - I would suggest going with either a conventional scope or red dot than the EoTech on a pistol. Mounted on a revolver, it would extremely bulky...plus the 557 has the ballistic reticle calibrated for the .223...
Several of the members on here love the Ultradot for a tube-style red dot, while others prefer the smaller format of the FastFire/J-Point/Delta Point - hopefully they'll weigh in.