I am buying a smoker, probably a charcoal one because it should produce more flavor but how hard is it to regulate the temp? Which do you recommend ?

If you want to go 'pro' type thing. Look at pellet smokers. They're normally just smokers and not BBQ grills. http://www.bradleysmoker.com/
That's a cabinate style model. A lot of the smokers use electrics to control temps and smoke the pellets that are fed into the smoking chamber from a hopper.

I have not found it to be too hard once you get used to it. I use a Weber Smokey Mountain and, on days without too much wind, once you get the hang of the vents, it's great. But, unlike some electric or gas models, you do have to pay a lot of attention. It is not something you can just walk away from (which is more the type of cook my dad is). This website has a lot of great tips: http://virtualweberbullet.com/.