Hmm, tough decision.
Although, I'd really miss having a .22LR, I guess I'd have to be realistic and go with a carry pistol as my first purchase.
I'd have to say I'd buy another S&W 642 snubbie which is my current "always, when I'm not carrying a 1911 instead, gun". It's a good gun for all occasions, it's relatively cheap and they are easy to find at the local gun shop or gun show. However, if I came across another Colt CCO (or the same sized Kimber Compact) first, I'd probably buy it before the little pocket revolver. The CCO, with it's Commander slide and alloy Officer's frame, is hands down my favorite CCW.
After that I'd basically start replacing most of what I have now. I think I'd simplify my collection a bit though. There'd probably be more that I wouldn't buy than any additional to my current collection. I don't think I'd replace all the guns that I have now.