V-wiz I had the same plan when I built my WFO but never did the smoker part. The learning curve using the oven itself to smoke or slowcook meats is really more then I cared to invest in especially since I built my UDS. I did put in a butt once when the temp had dropped to 300 and pulled out in the morning when the temp was at 195 and it was very good, not UDS great though.
Once I fire my oven for pizza and the temps get over about 600F, the carbon burns off the walls, I can fire my oven on Doug Fir and finish with oak and maple without any pitchy flavors. Grease would burn off too.
I based my oven plans on those by Rado of traditionaloven.com. If I had to do It again I would make a shorter wall height as I made it big enough to cook a turkey and now I doubt I'll ever need that much heighth.
That said, having a pizza oven makes pizza night at our house very fun and interactive.
Pete-my first UDS,a brick pizza WFO, a leaky Chargriller offest, wifes Weber Genesis gasser, and now a Lightening Fast RED Thermapen