Well, it depends on what case it is, what you want it for (noise levels, cooling, space...) and price.
Is there any point getting the e2160 as opposed to e2140? Will it overclock farther?
Yeah, it's only like $3 more, for +200MHz I think its worth it.
@ fortyways: Yeah I'm going aftermarket cause I don't wanna run into heating problems whenever I want to go further when I reach my max...