Sfx power supply recommendations

[JeeperCreeper]

So I'm looking to upgrade this HP 6300 desktop I have into a relatively cheap gaming PC, mostly to play old games from the early 2000s and maybe some more modern titles. It has an i5 processor (I might swap out for an i7 3770k) and Im going to be running 32gb of 1600 RAM. I plan on running an AMD 6600 GPU. It's a small form factor case, so I need recommendation for a budget friendly power supply, at least 500w. I know cheapest isn't always best. What are some decent brands to look at? Also, what are things to consider when looking for a power supply?

I should mention, yes I know the video card won't exactly fit inside said case, I have plans for that.

[Grendel]

Not familiar with the HP 6300 PCs but be careful with your plans since many HP PCs use proprietary power supplies which may severely limit upgrade potential.

[JeeperCreeper]

I know there's adapters to use an ATX power supply to the HP board, not sure if that translates to SFX power supplies though. I might end up with an ATX power supply sitting outside the case, which I really don't care how it looks if it works.
I'm not trying to make a killer PC, just upgrading a budget friendly rig that I already own and is not being used right now. If it ends up being too expensive, I'll likely stick to upgrading the RAM, and choose a less powerful GPU, like an AMD RX 580 which I know will work with what I have in there.

[ejacksophoto]

Note that "SFX" is a standardized size of a power supply and has nothing to do with the "SFF" name that HP used for those old towers. The power supply on those "SFF" HP towers are not "SFX" standard. You can buy an SFX power supply if you want something that will take up less desk space when it is sitting outside of the computer case...because it's still not going to fit in that HP case like the original power supply. HP used a proprietary "L" shaped power supply for those.If you buy an SFX power supply, it still uses the ATX standard for its cables. So if you need adapter cables to use a standard PSU with the HP motherboard, that will be true no matter if you buy SFX or ATX.

Honestly, just buy an RX550 or similar graphics low-profile card that actually fits in the case and doesn't require a beefier PSU.

[JeeperCreeper]

Well, if I go for the larger graphics card, I intend on doing some mods to the case to make things fit. I'm also aware of the HP power supply (and basically every HP component) being proprietary. I'm likely going to have to fit a new one outside of the dimensions of the original case. Maybe we will just have to wait and see what happens. Maybe I'm just a hot rodder that's not afraid to do something wild for no good reason.