I would recommend the i3-2120. It's a much faster gaming processor; http://www.tomshardware.com/reviews/gaming-cpu-review-overclock,3106-5.html and http://www.tomshardware.com/reviews/gaming-cpu-review-overclock,3106-3.html
... especially if you upgrade to a faster card in the future.
The i3 runs so cool, the stock cooler will be more than enough. And you can always add an aftermarket cooler later.
Btw, if the board you spec'd is the board you plan on using... the i3-550 won't fit. The i3-550 is a LGA 1156 socket, the i3-2120 is a LGA 1155 socket.