OK... as a previous Good Guys employee, I have done extensive research so incase a customer, like you, ask.
NO, YOU CAN'T PLAY AN SACD, or DVD-A in a regular CD player, DVD-A is to be played in DVD-A capable DVD players ONLY. Same with SACD, but now, SACD has hybrid, which means aside from the SACD track, it has a 16-bit PCM track accompanying it, which makes them playable in regular CD players. You're right, with that, you won't get a performance increase because it is the same 16-bit track that you're listening to, not the SACD.
There has been many debates over the formats, and I myself like SACD better. Reasons? The >2.8 Ghz sampling rates. Which would make the digital curve as smooth as the analog counterpart. With good speakers, amps, and a kick ass SACD player, you can hear music the way it's meant to be heard. SACD is not a surround sound format, but has an emphasis on soundstage and clarity. Go to SONY.com and do some research before nefing.
EDIT: Check Pioneer, last I heard, they have a pretty good combo for ~$1000.00