The new AMD chipset 870 and 890 (all series) support SATA III so ASROck with 870 or 890FX support the SATA III SSD or HDD.

Regarding the SSD that is an excellent choice I'd go for it and isn't necessary that u change the mobo u can buy a SATA III card like this: http://www.newegg.com/Product/Product.aspx?Item=N82E16816115072&cm_re=sata_iii_pciE-_-16-115-072-_-Product