I have two doves from my stage days. They are retired now and living off of the cash that they generated during the time that they spent in my shows. When they tell you that doves have a life expectancy of 12 years, don't believe them...I'm positive that these two birds will outlive me.
Doves are gentle creatures by nature. And, quiet cooing? Not hardly. My doves are damn well loud. They wake me up at the crack of dawn with their cooing and "laughing." Yes, that's right, doves laugh.
Finding them really is difficult. I gave up on getting the classic white doves and went with a pair of African Mourning Doves. They have a black ring around their neck and one is an off white whilst the other is a light brown in color.
Doves are not easy to train. In the intelligence region, they are probably in the lower 5% of birds in general. However, once you become familiar with their habits, you can decide which of your birds will do the best job with any given trick. And that is the key.
I'm sorry that I can offer no help in where to find them. Personally, I went to a local pet shop and ordered mine. I got two older birds which weren't hand raised, so they were skittish, at best. After months of gentle handling, they became warmed to the idea of being in hand, but that didn't stop their desire to fly off at any given time that the spirit moved them. I found that one would willingly lay upside down on my open palm, but the other refused that fully (again, you have to observe their behavior and then figure out what you can get away with).
The problem is that society is becoming more and more against the use of animals in any kind of act. This is particularly a problem in the UK specifically and Europe in general.
A good site to look into purchasing doves at would be
http://www.doveline.com/. You might want to send these folks an e-mail regarding where you could possibly buy doves in your area. If anyone knows, I would imagine that they will.
Mike.