My Vapor Store is very reputable. They are a forum supplier and if you go to the coupon code thread, you can find a 6 percent off coupon there as well. As for juice, try a 50/50 to start off with. Once you start using it, then you can decide whether you prefer a high VG percentage. More PG means a stronger throat hit. More VG means more vapor. Nic content depends on how much did you smoke on a daily basis. If you are/were a heavy smoker (more than a pack a day), then start off with 18 mg. Or since you're going with the iStick and the Nautilus, you may want to start with 12 mg. If it is too much for you, you can lower it later. If it is too little and you find yourself not being able to give up the analogs then you can increase it.
As for flavors, it really all depends on each person. What I like may not be what you like. If you have a B&M near you with a tasting bar, you can go and try out different flavors to determine which ones you like. I was a menthol smoker, so when I started I bought a ton of menthol juice and never tried any of the tobacco flavored juice. Pretty soon, I found myself trying and liking fruit flavored juices and now I don't use menthol at all.
As for flavors, it really all depends on each person. What I like may not be what you like. If you have a B&M near you with a tasting bar, you can go and try out different flavors to determine which ones you like. I was a menthol smoker, so when I started I bought a ton of menthol juice and never tried any of the tobacco flavored juice. Pretty soon, I found myself trying and liking fruit flavored juices and now I don't use menthol at all.