I like training collars that have a vibrate and electric stimulus over beep and electric stimulus but my field collar/hand unit is the Garmin alpha 100 with the TT15 collar and that does not have vibrate. My reason behind this is, I sometimes run a beeper locator collar and I've had dogs associate the beeper collar with a warning beep.
How I train/introduce my dogs on an e-collar. I start at usually a 3 or 4 on stimulus out of 18. I always introduce e-collar with the come command, never any other command YMMV. We go out on a check cord. I let the dog do it's thing and I say come. If no response, they get a beep and a tug on the cord. I repeat the command and if there is no response they get nicked and a tug on the cord, at this point I real them in and praise once they start moving to me on their own. I repeat this exercise until they get it down 100% of the time on the check cord and then we move to the same training off the check cord. Sometimes you have dogs that take huge steps back and have to revisit the check cord method, sometimes you'll get a dog that you'll never need any electricity and the beeper will be the only stimulus they ever need.
As for the amount of juice. I don't think I've ever gone above 8 out of 18 on a bird dog and not much higher on a bear hound, maybe a 10 or 11. Just keep in mind, it's a correction, not a punishment. Watch the dog react to the stimulus, the amount of electricity should be just enough to take his mind out of his narrow field of view, nothing more. If you're ever angry at your dog, put the e-collar away.