Having just recently built my own HT, I've done a lot of research, and came to the same conclusion...The Panny G10 series was the best picture for the dollar I found (and one of the best at any price). I bought the 50", and the largest size available is 54".
I also wanted relatively flat speakers I could hang on the wall. Not finding what I wanted in my price range, I made my own by building a flattish box approx. 7' wide x 14" high x 7" deep. Then I purchased in wall L, R and Center speakers and cut the baffle accordingly. I used pillow stuffing in the box, and it mounts to the wall with threaded studs mounted to the wall studs (that way I could hang it on the studs while I attached the nuts and washers). I made a similar, somewhat smaller box to mount on the ceiling for my surround speakers (in ceiling, round speakers with rotatable tweeters). But just mounting them in the ceiling would be a great choice in most situations.
The box and speaker grills could even be painted to match the wall for an even more stealthy look (high wife approval factor).