95 % of my computer use is browsing, e-mail, office suite, tv and movies. 1 . What is your suggestion from the current IMac range, considering that I want to keep my iMac for at least 4 yeas. 2 . Do i need more than 512 Mb of video memory ? 3 . How much RAM do i need? 4 . Do i need an ssd ? 5. 21.5' or 27' . Thanks in advance.