Newegg comparison
They look the same to me except the 431 has a 3.0 usb port on the front while the 430 doesn't. For me, I like being able to plug in USB drives/External HDD in the front instead of reaching around back. I would choose the 431
Have you considered the HAF 912 case? It's a very nice case
http://www.newegg.com/Product/Product.aspx?Item=N82E16811119233&nm_mc=AFC-C8Junction&cm_mmc=AFC-C8Junction-_-na-_-na-_-na&cm_sp=&AID=10446076&PID=3938566&SID=