How to multiplex a two-way data line?
What you want is an 8:1 multiplexer/demultiplexer.  You can get them as an IC, but I don't know if that falls under your idea of a "specialized" IC or not.  It's the kind of thing you would use in a freshman digital logic class.

If that's not basic enough for you, the block diagram still shows you what you need to build.

The bottom half is your MOSFETs.  The top half is called a decoder if you want to get that in a single IC.  You can also get the inverters and 4-input AND gates as separate ICs, or you can build those from transistors if that tickles your fancy.  Depends how hard you want to make it on yourself.