The multichannel will also play in stereo. I have a Sony DVP-S9000ES DVD/SACD player that is stereo only. It plays multichannel discs fine. I wouldn't worry so much about the formats, sound quality has more to do with the recording process. I've heard good and not so good recordings in the single layer, hybrid and multi-channel format. Just using SACD's limits your musical selection enough, buy which discs represent your musical tastes, and don't worry about the format. That's just my opinion.
Regards,
John
Regards,
John