Wanting to Try a 2 amp set up need help

I have a single channel tube amp. I really like the Dirty sound its just what I like. But since its single channel the clean is not all that clean plus I need to switch from dirty to clean in more than one song quickly so im thinking of trying a 2 amp setup one amp for dirty and the other for clean. I need to know what Im getting into going this route however lol. Can I buy a head for clean and use and a/b switch for clean and dirty and hook both heads up to a single 4x12 cabinet or do I need another cabinet? Im not sure. And what kind of issues am I looking at going with this setup live. Like most club level players theres no guitar tech to help me if things go south at a gig so Is this a nightmare waiting to happen or is this a fairly manageable endevour.
Thanks

I've got one of these and it works great. I used my Carvin head along with my Fender Twin Reverb and used the headbone to switch between the two using my Twin Reverb speakers. You can also use this as an amp switcher using two different amps, but they also have a switchbone which is specifically made for that. These are more expensive than a/b switchers, but they are much quieter. I tried an a/b switch and kept getting a hum.
http://www.tonebone.com/tb-headbone-vt.htm
Gcjammin1

The two amp into one cab switchers are great. I've used radial's and also Ultimate Attenuator makes one called the Ultimate Amp Switcher which is the one I currently use. I use my Marshall 2203 and Fender Bandmaster head through either a 4x12 or a 4x10.
http://www.ultimateattenuator.com