Hello

Im considering of buying my first mining rig, and I don't want to do major mistakes investing half a grand on this, so any ideas would be appreciated
I have only tested mining with my 1060 and im currently mining eth with around 30% profit, but what coin to focus later when ethereum moves to Proof of stake?

Im considering the RX 570/580's but im also concerned whether to buy 4GB or 8GB versions. Somewhere was written that 4gb cards cannot mine after few years as the DAG goes up, others claiming not to worry about this...

The thing is, my flat goes quite chilly specially at winters, so it would be a good source of heat at the same time and my electricity is quite cheap too

The question is: What cards should I buy which operates relatively quiet, should I be concerned about memory types (Samsung, Hynix, etc) (somewhere was written that Hynix is doing good with 570/580's),
should I go with 4gb or 8gb cards and also, what coin should I be focused on after ethereum is not mineable anymore?