[tonyvdb]

What is the purpose for the speakers? are they for a home theater room or just background music?

EDIT:
I guess I will just give some suggestions.
First of all in wall/ceiling speakers are very hard to place properly and do not usually give you great sound on a budget, bookshelves are a much better way to go.
Placing speakers in the ceiling is a last resort as this is very poor placement for theater sound because the sound is directed down at the floor and not at the listener. The highs get lost and you end up with muddy and unclear sound.
Here is a list some speakers that are available.

 

[tonyvdb]

At the very least dont put them in the ceiling if possible this really affects the sound quality.
For in walls ones that have the tweeters angled to point in the direction your sitting is a much better idea but as I said you will spend about twice/three times as much on in walls if you want quality.
Something like these would be a start for the surround channels.
And these for your left center right channels.