Hi I recent got a early 2008 20” iMac for free and was wondering. 1 if I upgrade the ram and put a ssd in will it be usable for light internet use and downloading small files. 2 is there a big difference between 4gb of ram vs 6gb of ram? 4 gb of ram costs 20 bucks and 6 gb costs near 70. Thanks for your help in advance!