Hi all!! So i'm about to order new MBP 15' 2.4. Will be my first MAC. I see that the memory upgrade can be done myself so i'll keep the standard 4GB and take care of that later. I would like an SSD though. Wondering how does the SSD and HDD thing work. Im ok with goign from 750gb 7200 to 128 gb SSD pricewise but spacewise, its kinda small and 256 gb is way expensive. If i go with HDD 7200 rpm whata re options to update to SSD other than having an external. Can i personally replace my HDD to SSD or add another SSD in the box. gimme a scoop on the best convenient and cost effective cases.