Irrational Number Line Games, LLC
Here are some big 'Clix guys I have used for Space Marine alternatives in one project before/. Basically, I think bigger is a mandate for the 40K universe. You can see compared to the reference SM that Crimson Dynamo is a size up. And he's not blocky, like 40K terminators. I'm sure there's an acutal thing this would be a good proxy for in 40K, and I'm just filling out my Iron Snakes and really like the design of this model. So, it's just that simple.
And simple conversion, too. The guy in the front got an extra clawlike bit I had for and arm. The chaplain to his left (your right) got a golden mace for spiritual motivation purposes, so I swapped his gun to the left hand. The guy with the power sword also got the gun in the left. The apothecary to your far left and the rest are righties. Two of them have power daggers (or short swords) in their left hands. So in addtion to the piecewise variety, I have five with close combat weapons and five without.
The guy with the claw is also on a bigger, actual 40K, base. Chappy has part of the 'Clix stand there (which for some reason has a lot of glare in this picture even though it is just flat black like the rest of the base). A couple others had bits of base on the foot when I cut them loose. I shaved them flat, but not flush with the foot resulting in some height variation. Yeah, I know they're Space Marines. But they're my Space Marines. All in all, a nice squad of ten.