You really just have to experiment and try a variety of American juice makers. Menthol is one of those flavors that is all over the spectrum. Some have a little tobacco flavor mixed in, some do not. Others lean toward the minty side of things.
If you break down and decide to mix your own, you'll need concentrated flavoring. I've gone through a dozen menthol flavorings and the only one that does the trick is Menthol from FlavorArt. By itself it's OK, not great. But you can make a mixture that works well for adding to other flavors.
Menthol Base - get yourself the ingredients for mixing and start with about 20% of menthol. You'll need some nicotine base liquid, some pure PG/VG (no nicotine) and the flavoring. These three ingredients are all you need. Use an online juice calculator to derive the correct percentages for desired nicotine strength.
Once you have your Menthol Base mixed together you'll need to decide what end result you're looking for. Say you want to get in the ballpark of a standard menthol analog. If so, you'll need a tobacco flavor. Get one that says RY4 or Pall Mall, those tend to be pretty reliable. Then it's a matter of experimenting.
Try taking your menthol base and mixing it 50/50 with the RY4 (or similar tobacco juice). Smell it first to see if you think it's in the ballpark. If not, keep changing the ratio until it smells about right. Then start loading up cartos and tweaking your mixture until you find the happy spot. It's really not as hard as it sounds.
Now you can also take the Menthol Base and add it to other flavors too. Say you've got a Blueberry you're fond of. Try adding a little menthol base to it and see what happens. You won't need to add very much to a lighter flavor like Blueberry to have a big impact. Heavier flavors like tobacco require more menthol than lighter flavors for the menthol to show it's presence.