Supernatural crossovers and recomendations

[dnoellert]

I thought I read a couple of Mag 7 / Supernatural crossovers where the Winchesters meet the ghosts of our boys, but I can't seem to find them any where. I seem to remember that Vin's spirit was somehow separated from the others and they refused to move on with out him. I think they were also trying to prevent an evil from being released, but I could be mixing up my stories. Hopefully this vague description will ring a bell for someone.

I'd also be happy to accept recs on which M7/SPN crossovers you liked the most. I'm new to reading Supernatural and haven't figured out where the best sites are yet.