I have a 7.1 preamp,is there a 7.1 dvd player?

There are 7.1 DVDs but only through the digital outs.

Dang, I had no idea. Are these discrete channels? How many such discs are available?

They are actually 6.1 Unsound but they are the reason receivers converted to 6.1 with a rear center. Almost all receivers are now using 7.1 and creating stereo rear centers or back surrounds. Of course some have even more channels but they are simulated at this point.

I split my rears of SACD to try the multi channel experience, but I dont have enough material as of yet to decide if I like it or not.

I believe Onkyo SP 1000 has 7.1 analog audio out, but you might want to double check.