Well its pretty easy to make money now, I say try both see which one you like better. I have an archer alt and I have every single bow from the Khergit bow up.
For me the longbow was much too slow, by the time you draw it your target has moved on a fair bit, so you have to move the bow on top of the target where it is now. While you are doing that the reticule is getting bigger and bigger so you don't have much time to adjust your aim over target before you have to shoot. Shooting the longbow for me is just painful.
The warbow is much faster to shoot and I prefer it over the longbow, before the last archery nerf if you asked the same question I would have told you to go for the strong bow, but now archery does so little damage I am not sure if its worth it. Anyway try which ever one calls to you right now, since money is easy to comeby you can always try the other one further down the line.