I found some unused HD (1.2M) ones, but those are not usable on the TRS-80, from memory. There were plenty of DS-DD ones, but they have all been used previously on a PC. I found 4 with unimportant stuff on. Many of the others could be used after being subjected to a bulk eraser, or with a guarantee that they would be erased immediately, as they may contain confidential data.
Send me a PM with address details and I'll send the 4 DS-DD ones. No guarantees, as they are over 25 years old.
BTW I have lots of original PC software on 5.25 (and 3.5) floppy disks if anyone collects that. Ventura, MSC, MS Assembler, FoxPro, PC Tools, and dozens of others. As well as cover disks from computer magazines.