center channel speakers --- low height

I am installing a home theater and I have a size constraint for the center channel speaker. It has to be no higher than approximately 6 inches. The Revels and the Sonus Faber won't work and I didn't particularly like the sound of the B&Ws that would fit for this application. Any recommendations?
What are your other speakers? It's very important that your speakers match. I would re-visit your design before installing mismatched speakers. It will be worth the effort in the end. If you can't accomodate the center channel you want, phantom mode with no center is always an option. Here a re a couple of links.
You need your center to match your mains. This would be a major mistake if it didn't. Matching the sourounds is even better but now as important.
Phantom mode is the way to go if you don't have to make it sound right over a wide area. If it's for just 1 or 2 people the phantom mode will frequently sound better than using a center channel.
I agree with Rives, and know several people who have gone from using a center channel to phantom center mode and prefer the latter.

To widen the listening area in phantom center mode, you might try this: Toe your left and right main speakers in severely so that their axes actually criss-cross a little ways front of the center listening position. Now for listeners off to one side of center, they are more on-axis of the far speaker and way off-axis of the near speaker. Since most speakers are somewhat directional (especially in the upper treble), the far speaker will be a bit louder than the near speaker which will tend to offset the latter's earlier arrival time. The result is good soundstaging over a much wider area than you'd have with main speakers pointed straight ahead (or only toed in a little) in phantom center mode. You may have to experiment around a bit to find the optimum speaker separation and toe-in angle to give good center-fill from well off-axis.

This may not work with all speakers but it doesn't cost anything to try, and will almost certainly sound better than a system with a mismatched center channel.
If you have to toe toe your speakers something is wrong. If your speakers are decent and set up right they should image fine to produce a phantom center. If you have to start playing with position your soundstage is not correct. When you play a cd or volcal piece and close your eyes the singer should apper right in frount of you and the instruments around them. If you are not getting this effect then setup or equipnment is an issue.
These suggestions are very helpful. I will not mismatch speaker manufacturers for the reasons stated. I like the idea of a phantom center channel and will give it a try.
In the meanwhile I called Sonus Faber because I noticed that their Domus center channel is low and might work. They felt that a combination of Domus center channel and surrounds with Cremona Auditors would work well. Do you all agree that this could be a good solution?
i use the sonus faber wall speakers x 5 ( one of the wall speakers as a center)...

i think as long as stay within the same mfg. you might be okay (ie keep the sonus faber house sound).
That would work. As long as the frount 3 match so voices don't sound different in the sides and center.
Programmergeek and Mikesinger thanks for the response to my follow up question. The combination of Sonas Faber speakers is probably the way I will go. Appreciate your advice.