I have an SWR 4004 with the WM 4x10T. I'm starting to think about a second cab for this setup. My first instinct is to match it with the WM 1x15T; however, that cab is rated at 200W. The 4004 runs 400W at 4 ohms or 200W per cab. Seems like the edge to me. I play a 5, so it would be good to get that 15 in there. Any suggestions?