Need help with trans swap info please.

[69*Goat]

I am starting the search for a 6-speed manual so I can make the change from automatic to manual in my 69' GTO. At this point, I am not wanting to buy a "Brand New" kit, because I bet, I could get a good used trans, and then cobble the rest of the parts up separately. I am running a Pontiac engine (No LS here). Have any of you guys made this conversion? If you have, which year 6-speed did you use, and what do I need to shy away from?

Please let me know.

Thanks in advance.