Stinger,
I own the first two, and am looking for a good 34 also.
The 18 is probably the finest-made Smith I own, all things considered. It has a wonderful trigger in both SA and DA, is very accurate, etc., etc.
The J-frames you mentioned are great guns also, including my 63. The last time I had it at the range I shot better groups with it than I had the 18 the previous time out. But that was likely me finally getting the hang of shooting a J-frame. Their smaller size makes it more difficult to keep from moving the sights/barrel as the trigger is pulled.
My reasons for owning these are to train new shooters and to help me review fundamentals of DA shooting periodically in order to better shoot my carry gun and house guns, which are .357s. The J-frames, though more difficult to master, are a better choice for breaking in folks with very small hands; i.e. women and children. The 18 is great for teaching both men and women with average-size to larger hands.
One thing which might be helpful to remember is that 18s typically have tight chambers. Because of this some of them have chronic extraction problems, depending on how dirty the ammo is and how well they've been kept clean in the past. When I first acquired mine, I had to use an electric drill with pieces of lead-away cloth to clean those buggers out in order to avoid the problem just mentioned. I was successful to the degree that I can shoot around 150 rounds(about the most I shoot in one session with a .22) before any of the empties begin to extract with difficulty.
My 63's chambers are bored a tad larger and don't give me any extraction problems. But then that may be the reason 63s aren't quite as accurate, as a rule, as 18s.
Be ready, regardless of which revolver you get, to change out the grips from service to target or vice versa, depending on which you or the primary shooter prefers. My 63 came with service grips, which were entirely too small, not only for me, but also for others with smaller hands than me.
Let us know and see, if possible, what you find.
Andy