I saw this posted in another topic, not sure what processor it is for though (see image below). As for the performance of Artic Silver 5 vs generic thermal compound, that depends on the quality. I've never used the CM compound before but i'd guess that the difference wouldnt be any more than 2-6 degrees.
More fans might be a good idea. I'm using a midtower lian-li v1000b and I have three 120mm fans (one front, rear and side.) My case could benefit from converting some 5.25 bays to a fan so yours most likely will as well. Keep in mind that you would have a 140+120 in and only a 120+psu out so it might be a good idea to have another exhaust running on low (but thats just my opinion)