Hercules brand bass stands are my favorite.
Do you think this will work for the Firebird and Thunderbird?
Hercules Stands GS422B PLUS Dual Guitar Stand with Auto Grip System and Foldable Yoke
I use both, but typically it’s a straight jack into the amp and a straight or angled into the bass. I have had several angled jacks break off when hit or pulled wrong. When they break off they usually leave the straight end of the connector stuck inside the jack. Not a huge problem to get out on the bass, just remove the control cavity cover and push the connector out from inside the bass. On an amp, when the angled plug breaks and leaves the straight connector in the jack it’s a PITA to get out. Gotta take the amp apart or at least the cover off to get to those jacks, not fun, and maybe even dangerous if you aren’t careful.