Join Date: Dec 2010
Location: southern Arizona
A lot depends on your price range. If you want to get a feel without committing a lot of money, Wintec makes serviceable saddles that won't break your budget new. Depending on the area, you might be able to find one used, but Arizona is a tough place for finding used English saddles...
You also may not need a 19" saddle. You might, but most English saddles have a larger sweet spot (level area) and a more gentle rise to the rear than most western saddles. I find a 16" western...well, it certainly isn't too large. I've used both 17.5 and 18 inch English, and the 18 inch is roomy without being too big. The 17.5 is a jump saddle and quite flat, so a dressage saddle may differ - I don't own one to compare.
Depending on where you live, one option might be to call someone who trains English riding and shell out $30-40 to go take one lesson. I know Tucson and Phoenix have trainers, although they thin out fast as you get farther away. Also, if you go to a shop that sells English, you can certainly get an idea of what size you'll want, the difference between an AP saddle and a dressage, and MAYBE find a used saddle.
In Tucson, I'd recommend the Saddle Shop (7930 E Speedway Blvd), corner of Pantano and Speedway. They have both new and used saddles...I didn't buy one from them, but I later bought some tack there just to support an Arizona store that carried English gear. I assume Phoenix would have more variety.