Looking to source some cable guides similar to these in the photo - double for the downtube and triple for under the bottom bracket. Not an easy find on the general online shops. I figured the mechanics would know where to get them. Thanks for the help.

55/Rad

Framebuilders use these things more than mechanics. Cable Stops/Guides - Frame Building Parts

For whatever reason, I can't see the photo, but here's another source from a framebuilder (these are brass and spiffy): Brass Derailleur Adjusters | Kirk Frameworks

I use electrical plastic cable guides when the situation arises, 6mm or 8mm just $2 for 20, similar to those single guides in your link

did a single speed recently that needed a rear brake, looked pretty good in my opinion, black on black cable

though.. if that shop was local that you linked, i'd use them...still cheap

I have recently took one to a Home Depot (hardware section), and a person there help to pick out a replacement for me.

Good luck

Amazon, should have what you're looking for

Thank you all for your replies and suggestions. -55/Rad