ADS produced great speakers! Back in the day when I thought I needed a center channel speaker, I used a pair of L400's laid on their side, woofer-to-woofer, with the tweeters at each end. They worked out great. Since I watch a lot of older movies, many in mono, I prefer the sound out of my main speakers, L1290/2's, which spreads the sound out wider, so I don't use a center channel anymore. Probably heresy to most, but works for me.
Roy's choice of the other models is good also; have personally used the L420. You can't go wrong with any of them, size probably being your determining factor.
Al