I tend to favor the Bandai's Action Base stands - they come in different colors and the platform parts of the stands often come in different shapes, but usually they do pretty well. I've used them to hold up the Siege Seekers in their jet modes in this Cybertronian battle diorama I made:
Here's a few examples you can find online, though there's probably a bunch more:
https://www.agesthreeandup.ca/produc...bafab78f&_ss=r
https://www.agesthreeandup.ca/produc...bafab78f&_ss=r
Search results for "Bandai Action Base" on Amazon:
https://www.amazon.ca/s?k=bandai+act..._ts-doa-p_1_18
Hope this is at least a good start.