Yeah, man! I have been into the techno and dance stuff since almost the beginning.
My first cassette I bought was the
Zero: Ravenous record. You can find it on Amazon now for like a hundred bucks. But maybe some other site has it cheaper. It is a classic jaunt into amazing beats and techno tunes. I still listen to it occasionally. It still holds some great tunes and manages to not sound as dated as it actually is.
Another one that got me hooked was
World Wide Message Tribe: Take a long hike.
But I think fondly on all those first amazing records. The
Prodigal Sons: Texno Theology and the
Prophecy of P.A.N.I.C.: Manic Panic were among my favorites. Then bring in some early Scott Blackwell stuff and some of the MotionFactory tracks and that classic classic piece of work, Jyradelix, and you are in a good place.
But unfortunately, like 404 said, most of that stuff you can't get anymore. And if you can get it you only find it for high prices or by looking through the entire internet. (it is buried there somewhere).
As far as mixes go, I would first hit up
http://www.dj404.com/main/mixes.htm and scroll down to his earlier mixes. Still not as oldskool as you are looking for but definately worth checking out. There are some mixes floating around if you look.
Hope that helps.
z.