If you really want to build a pentium 2 you have to search for it...
My advice would be finding forums that are local to you and create a thread saying
WTB Pentium2 Or looking for old hardware.
If you were arount montreal area I would gladly give you a Pentium3 motherboard with a P3-1000 or similar with all the components needed.
But for a Pentium2... you might need to give it Windows 95 or 98se or at latest 2000 (Minimum 400Mhz with 384MB Ram)
For windows 95 and 98, it will be a big pain finding the drivers...
Perhaps you can tell us why and what do you plan to do with this.