Get an H77 motherboard, not H61. While the H61M/U3S3 you picked should in theory work with Ivy Bridge CPUs, Asrock does not list the i5-3550 as a supported CPU. An H77 motherboard will ensure you won't have any problems.
-What is best in life? -To crush your enemies, see them driven before you, and to hear the lamentation of the women.
since you won't be doing crossfire you can get this board: http://www.newegg.com/Product/Product.aspx?Item=N82E16813157313
and this case: http://www.newegg.com/Product/Product.aspx?Item=N82E16811146078
the NZXT is the best all round budget case for price, cable management and features. Thermaltakes budget cases are ok (I've built many computers in both) but the metal feels the cheapest and flimsiest on any case I've ever touched. they have very little space in certain areas as well. behind the motherboard tray on the top of the case (where top fans mount) are very tight.
"There is nothing new under EA." - Fony http://valid.canardpc.com/show_oc.php?id=2363251