All good answers here; but back to your original question. A recurve will make the transition a little easier, and in most cases, is easier to shoot well than a longbow. Just to add a little confusion to the choice, there really are two kinds of "longbows"; the more traditional straight limb and straight handle "Hill" type, and a more contemporary shorter RD (reflex-deflex) type with a handle that shoots more like a recurve than the traditional longbow.
All that said, for TARGET shooting, I'd suggest something more along the lines of a 40# recurve to start out. You can find a decent one at auction for $100 - $200 to start. The big advantage of that 40# bow is you can focus on developing your form without having to spend a lot of time developing the strength to come to full draw and shoot as many arrows as you do shooting targets. If you decide to stick with it, you'll have a little experience to help decide what you want in your next bow.