I have a DSA SA-58 I’d love to get an HB and trigger job for. Are you a smith?
I can make you a barrel, but I am not a licensed gunsmith. I can loan you the tools to replace your barrel. It’s really easy, just unscrew the old one and screw on the new one. If you are close to Nashville, you can drive down after it is finished and we can replace it together and then take it out for testing. FF hand guards are available from Entreprise or DSA for about $100.
The ones I make use an Israeli HB gas block so if you want iron sights, you will have to get some Israeli front sight parts. You can use either an inch pattern or Israeli gas plug.
The work of the trigger I have seen is a company that makes a device that depresses the trigger return spring and locks it out of place. Look over at the FAL Files for more info.
P.S. I see you are in Washington. Kind of a long drive.