I'm also starting work on my Skullcrushers-as-Bikers.
Most of them are going to be meltabikers, so I've been amassing a collection of Blood Angels infernus pistols to use as their meltaguns.
I don't really like the look of meltaguns used one-handed, so these pistols fit the bill perfectly for a berzerker with a melta in one hand and a chainaxe in the other.
Just testing out the bits to see which parts I'm going to use. I think I like the CSM Khorne champ head very much for my standard bikers, and I'll be using the Skullcrushers helms for the champs.
The torsos from 40k just aren't quite big enough for the Skullcrushers legs, so I think I'll end up going with the torsos from that kit as well.
Here's a quick mock-up: