The thing about peristaltic pumps is that they are used for precise metering of fluids - generally in a medical setting; for most uses, 1 liter/second is way too high. You likely won't find such a pump because there isn't a need for it in the niche those pumps are used; if you insist on such a pump, you'll either have to custom build it, or if you find such a pump, it's going to be fairly expensive.
There are three basic systems typically used for "automated bar" pouring - all will require an alternative method to meter the fluids:
1) Gravity feed
2) Pressurized system (generally via CO2 or nitrogen)
3) Windshield washer pumps
Note that if you go with #2 - you -will- want to use CO2 or nitrogen; using plain air can work, but it isn't generally considered "food safe" (which is why the beverage industry uses those gases in fountain drink machines). Be sure to purchase food-grade CO2 or nitrogen, and to use food-grade parts and lubricants, because industrial grade gases can have contaminants as well as machine oils in them, and the tanks (which you rent, generally) may have been used in a situation in which contaminants could have gotten inside the tank (perhaps the last renter opened the tank, and "cleaned" it, then put some other gas inside or something - who knows!).
Ultimately you'll want to make sure all of your parts that come into contact with the food liquids not only are impervious to ethanol, but are also food-grade or certified for food usage (especially if this is for a commercial setting or product - for a home based system, you can do what you want, as long as you and others using the machines realize the long-term potential risks).
Metering the product will be the difficult part; you could use a scale of some sort (or a similar weight/mass sensor), or you could look into an appropriate flow meter to insert into the output line (again, make sure it is a food-grade part and can be used in the presence of ethanol). Generally, though, a little variation in a mixed drink is not that big of a deal; most of the time, a bartender is not going to whip out a graduated cylinder or something to measure out each and every drink or shot. It gives it a bit of character in the difference, IMHO. So - simply doing a weight/volume measure should be fine. Even just timing the output may be enough (though that wouldn't catch an empty bottle/reservoir)...
Thank you very much for your response!
Considering what you wrote, I've changed my strategy to load sensors for determining the output volume. That gives a bonus of auto pouring the shot when a glass is put on the sensor.
Ordered two of these today: http://www.ebay.com/itm/360740315934
What I do need though is to start the pouring somehow. I was thinking placing the bottle up side down, but I still need a ball valve hooked up to a servo or something to start and stop the flow. Any ideas?
Maybe something like this and hook up a servo to it? http://www.ebay.com/itm/Rotating-4-Bottle-1-1-2-Ounce-Drink-Dispenser-bartender-shot-party-carousel-/230877773364