Only the DVD-800 is a Nikkai model. The DVD-100 is made by Shinsonic. It does play mp3/cdr/cdrw. The DVD-80 is, well, unknown. No one has been able to confirm actually seeing it to make comments.
It has been hypothesised (by me, no less) that Best Buys across the country are only going to get in one of the three models. So you'll either get lucky and have the Shinsonic DVD-100 at your store, get unlucky and have only the Nikkai available, OR get surprised and have the DVD-80 (surprised only because you can then come to Anandtech and let all of us know if it is a good DVD Player or not).
I already own the Shinsonic DVD-100 and in my opinion it is the best of the $69 players that will be available tomorrow. The Apex DVD-1500 comes in close second, and the DVD-1000 is a close third (only because it is missing the LCD on the front).