It's going to be extraordinarily difficult to find a complete bike from 15 or more years ago for sale; and whilst I cannot help you find one of those, I have another idea.

Let's take a look at Ryan Nyquist. He's been a professional rider longer than I've been alive, and his roots are firmly in the earlier years of the sport; and he's maintained that in his bikes. My point is it would be far easier, and maybe even cheaper, to modify a bike to your liking.

"Modern" bmx geometry is not a static mold. Frames come in all shapes and sizes now, and you can even get custom frames from Fit online. I imagine frames from the 90's were more aimed at dirt meaning longer chainstay lengths and more angled headtubes. If you don't want to learn the fascinating engineering of bmx frames, you could simply buy a complete Haro, which are mostly aimed at trails and have kept the old school cool, or start with their old school frames. Again, the only real difference in frames over the last 15 years is the introduction of chromoly steel and more choice in frame geometry.

For your other concerns, just pick up the parts that you want. Seat too low? Raise it up! Nyquist has been doing it for decades. Bars too big? Cut them, or pick up a set of smaller bars. Something with a 7.5" rise is fairly short by today's standards. You can also get smaller tires for relatively cheap. BMX bikes are like legos, you can make them whatever you want; and you don't need to buy an old bike to get that old feel.

Anyways, hope this helped in some way, or at least opened your mind to an alternative if you can't find what you want.