I think you'll be fine with using ceiling speakers as surround speakers if that is your question.
If you would like some product recommendations, I highly recommend Monoprice for the best bang-for-the-buck. Its easy to get screwed in the audio world if you don't know how much the stuff actually costs to make. So, don't get screwed.
Anyway, for in-wall speakers I use product ID 6816 and ID 4881 in my HT setup and I can tell you that they're excellent.
For in-ceiling speakers try product ID 7605. I don't have any of those myself, but they look good; and given that the drivers are angled (they don't fire straight down) you could angle them towards the focal point of your audio setup.