The Pyrat Summer Tea is a simplified version of the popular Long Island Iced Tea. It is a nice, far more relaxed recipe because it cuts the booze in half, relying on two rather than 5 distilled spirits, and it is the perfect, lazy drink for those hot days of summer.
This recipe focuses on the rum, particularly one of the fine rums produced by Pyrat Rum. The XO Reserve is mixed with Patron's Citronge (instead of triple sec), and a healthy amount of sour mix before receiving a lemon squeeze and being topped off with cola.
I would recommend making your own sour mix (recipe linked in the ingredients) because it is very easy and can create better drinks than most store-bought mixes. It is really no more difficult than making simple syrup. However, if you find that this drink is a little too tart (it is high proportion of sour mix), then I would suggest starting out with 1 ounce and working up from there.
While it may seem insignificant, I have found that the lemon squeeze is necessary for bringing the drink together and adding balance. It adds a quick freshness that opens up the other ingredients, much like adding a dash of bitters will do in other cocktails.
For the cola, you might consider stepping away from the popular brands like Coke and Pepsi and try one from the smaller, crafted soda companies. The best Pyrat Summer Tea I've had came when using Q Kola because it is a much lighter, less sugary version that does not hide the other ingredients. In this case I do recommend just 1 ounce of sour.