Potentially getting an early 20 inch '08 iMac, is it even possible to find a good OpenCore'd OS for this?

My friend has an old iMac laying around that I'm assuredly getting in the next year or two, I wanna prepare by figuring out the kind of OS to target for when I can mess with it. Is it viable past dosdude1's Catalina patcher, especially without upgrading the ram, or should I be searching for a different one to work with it?