Haven't ever been to a "Junkyrad" yet
but most of the parts that you need can be found there I'm sure.
Here is a past posts that discussed lots of the info you would need -
The list of parts required below came from this great site -
Parts you would need -
Q: What is needed to convert my engine to TPI fuel injection?
A: You'll need to find the following:
TPI plenum and runners
MAF sensor, intake hose, filter case
Injectors (19 lb/hr for 305, 22 lb/hr for a 350)
Oxygen sensor (if yours doesn't already have one)
Knock sensor (if yours doesn't already have one)
Intake air temp sensor (goes in plenum underside)
Coolant temperature sensor
Cold start injector sensor
Electronic Control Module (ECM or computer)
Re-route EGR and charcoal canister ported vacuum as per TPI setup
A/C bracket to TPI intake (upside-down U-shaped bracket)
The best (cheapest) way, is to find the parts through junkyards.
One last area of reading you will find great info on is -
BTW - it will become obvious to you as you read the articles, but be aware that most of the 92 and later F.I units DO NOT have a hole or provisions for a standard Distributor. There is a link on the LT1 site to have them modified, but you may be better off starting with parts that are compatible with your distributor equiped engine. Crank triggered ignition systems are always an option though...
Also 87 and later intakes would require updated heads or machine work to bolt up.
Hope some of this helps you in your quest to change over to TPI.
Post back with questions and someone will answer them.