[ADVICE] '68 /6 P/S conversion, unsure where to start

As Murray said, you can find used factory parts pretty cheap. Get a new pump, steering box, coupler, & buy a used column & You are ready to go for about $500. If you want, splurge on a Firm Feel or Steer & Gear box.
Spend the leftover money on something else cool. You can buy a nice set of wheels & tires with the leftover $1500