low power graphics cards that connect directly to PSU?
So my computer is old, and I really can't replace as much as I would like since 1. I wouldn't know what I was doing replacing everything and 2. I can't afford it. I feel like if I could replace my graphics card I would be okay for a while, but so many cards I see now just won't work. They all seem to draw power from the motherboard and require UEFI bios instead of legacy bios, which my motherboard doesn't have or support UEFI bios. So I would need something that draws it's power straight from the PSU and not the motherboard's PCI-E slot. The other issue seems to be power, or a lack of it since I only have a 500W PSU. So I would also need a low power GPU, but so far every card I see that's low power draws from the motherboard.
I've been looking for a while now for cards that connect to the PSU through either a 6 pin or 8 pin PCI-E plug, but I'm just not having any luck. Amazon is a complicated mess since they bunch up reviews and questions for similar products and toss them all into one place, so you can never tell what specific card anyone is talking about. Most other places I've looked just say something generic like "PCI-E card" which mostly just means it plugs into the PCI-E slot on the motherboard. It seems like every image posted of most cards is just a slightly different angle showing the side with the fans, it's like they want to show off their fancy lines in the fan blades or something.
It's really getting frustrating even looking anymore. The cards I could use that are within my price range (which is around $150) all seem to just be powered by the motherboard, but the ones with the connection I would need not only require too much power but are out of my price range. I've looked into older cards that would work, but for whatever reason they almost all seem to cost more than newer ones. So if anyone could help out and suggest something that would be great.
I'll list my components here just in case it might help