Thanks for the replies gents...I should have stated, not only for Mint Juleps, but Mojito's and anything else I may find intriguing with mint. Sounds like spearmint is the way to go....
With all that said, I now have a peppermint plant, an orange mint plant and a spearmint plant. LOL My wife was out at a nursery today and bought the first two without further information, and my neighboring asparagus farmer gave me a very small spearmint plant when I bought some asparagus this afternoon. Now I can try all three!

I'm intrigued by the orange mint and the aforementioned chocolate mint plant. I wouldn't have thought of more than just spearmint and peppermint.
Thanks again for the replies.