I am not a breeder myself, but work closely with my family who are, and I do the chips for our puppies and adults. We purchase the pre-loaded syringes from Revival, and also purchased the scanner from Revival (although that was some time ago and I can't remember how much it was). I do know that we got the scanner that only reads Avid chips, since that is the chip we use, and that scanner was less expensive than the others. The procedure is to scan after you insert just to make sure it is reading ok....but if your vet has a scanner, maybe they would scan for you at your regular check up, after you have inserted it?
I also do the vaccines, and I have to tell you, it took a while to get accustomed to doing the chips. Although it's basically the same, the chips are deeper and I still cringe every time I do one. This is even though it is very quick (once you get the hang of it) and they don't hurt but for a moment. Some act like it definitely is a moment of pain, and others act like they didn't even feel it. (Much like vaccines)
But all in all, it is not bad, if you are already doing the vaccines I would imagine you could do it. One thing is that I always have another person assist me by holding the dog very steady. I find that this allows me to work much more quickly, which is good for both me and the puppy.
Avid has two registrations available for the chips, prepaid and not. The prepaid is cheaper (meaning you buy it and then give it to the new owners), although it has gone up recently. We haven't purchased these since they went up, but I think they are around 12.00 now. If you use the other ones, it costs the new owner 18.50 to register one. If they don't get registered, the chip traces back to you, so you will want to be sure that you keep records on which dog you chipped with which number.
Sorry if this was tmi....didn't realize how much I was typing!