A while back we had a venture into that question, forgot what the size was, but i think it was over 50MB, i could load it easily on a monstrosity with 32GB of very fast (at that time) RAM and 8 cores.
All that is pretty much useless for you, and the only advice i can give you is get at least 8GB of RAM to work comfortably.
Linux is very good at managing memory, but there is so much stuff now in it to make it user friendly and look good that usually when all is said and done, 4GB is usable if you do not open a lot of programs at the same time, 8GB is comfortable for normal use, 16GB is probably enough for everything, except video editing and 3D modeling and rendering.
