Depends on what you’re doing I guess but for gamedev I would go with a 3060 or better. You may want to buy a 3060 12gb or a higher end 12gb+ card, if you plan on doing super high quality renders.
If you continue using Lumen it really doesn’t matter, as reflection captures are disabled when Lumen reflections are active. But I wouldn’t recommend setting it higher than 512.
On an 8gb GPU you can only place a handful of 2048 reflection captures before you run out of memory and your GPU driver crashes. A large scene is likely to require upwards of a hundred reflection captures… and I don’t know if they stream.