If you're set on in ceiling speakers, then you would definitely need the angled ones for the fronts.
In wall and in ceiling can sound alright. I've heard other setups with in wall and in ceiling speakers and they were pleasant enough and when you want a nice clean look to a room they can't be beat. However, you'll never get the SQ from them as you could from a box speaker. That being said, if you're ceiling is already pre-wired and you're not going to do some critical listening and you don't want crazy loud playback levels, you'll be fine.
What do you plan on using for the receiver?
There's also these
HTD Multi Purpose In-Wall and In-Ceiling Speakers
and these
Loudspeakers