Without prior 121 time, anything less than 2 years is a bit of a stretch just because of getting 1000 hours. You'll be in training for 2-3 months, building zero time. Then you hit the line but you'll be on reserve, so you could range from 20-75 hours of flying depending how much you are used. Sure you can pick stuff up but you're sacrificing your days off in doing so. Most people who are busting their butts to get 1000 hours did it in a little over 1.5 years.