I would try one or two cheaper Ry4's and work from there. Personally I'd say try a Hangsen RY4. It's inexpensive, very well mixed and very, very good juice. For a more tobacoo strong mix, Dekang (or DK4) is also plentiful and again, not overly expensive.
From there you can decide what you like, which notes you want more of, which you want less of (the tobacco, the caramel, the vanilla etc) over in bills exhaustive Ry4 round up thread, you'll find more Ry4's then you could possibly need or imagine. There's one that's right for you, of that I'm fairly certain. No two Ry4's are the same. Some can have similar traits (a Hangsen RY4 and a janty mix for example are similar) but no two are identical, which can make deciding if you like the generalised term 'RY4' a bit tricky!