This is my first Mac Laptop, I have a 24" Imac (Love it). 1.)Now I will immediately upgrade the memory, should I just get the ram at the Apple store or just hit Bestbuy on the way home? 1b.)If I don't get it at the apple store can i go above 4GB total? (6/8 GB? or is 4GB the absolute max?) 2.) If the New Pro's come out in the next 14 days I can return it (with restock) for any reason correct?