Wolf0, I'm a little confused on the memory issue. What is the desired memory on the RX480? Are there any to totally stay away from? And how can you tell what memory a card has before you buy it. I search for specs and it's not something that really seems to be listed. Maybe I'm missing it.
4GB is more than adequate. If you have 8GB it might hash slightly faster but a lot of the extra memory is not used for mining.