At FreedomSMokeUSA (the vendor with the most tobacco juices), you can makes any of their tobaccos be menthol (not the samples - the regular sizes have a dropdown where you can choose menthol)
Some people buy and dilute in PGA then PG (or buy prediluted) Menthol Crystals and then add the liquid to whatever juices they want menthol in.
There are also lots of flavors around with mint in them. Chocolate mint, fruit + mint, etc