My thinking...

So I got a Sigma 530 Super flash. While back I had an AB400, loved it, but ended up selling it. Now i'm looking at setting up a small studio for whatever comes my way. I was thinking of just adding on 2 Vivitar 285hv's or 2 Sunpak 383's to round everything out. My reason for doing this, portability and it just fit's betting in my apartment. Only real downside is cycle time on the Sunpak and Vivitar (without getting the adapter). Any other downside I might be missing? Compactness was the main reason on this.

Also, what would be the biggest sized softbox i'd want to use with the above flash units? I do know way later on i'd like to get some more AlienBee units..

Vivitar will put out a fair bit less light than than the AB400 I suspect, with slower cycle times, and you can't fire so often or they'll burn out. Otherwise light is light.