@Generale
Hmmm... Well, I think ISA slots would be your best shot - cut two of them so you end up with an end at both ends of the PCB edge for the best fit, and secure together with some stripboard or something at the centre. You sure you aren't thinking of building a Zorro slot? An IDE port is quite a bit more complicated, as the Zorro signals alone aren't sufficient to communicate with an IDE drive, you'll need some sort of intelligent controller too...
