System drive dead, looking for an SSD

So I have this ASUS motherboard (http://www.newegg.com/Product/Product.aspx?Item=N82E16813131603) and I need to replace my Windows system drive. I was looking at the OCZ Agility 3 (http://reviews.cnet.com/internal-hard-drives/ocz-agility-3-120gb/4505-9998_7-34715543.html) but I noticed it is 6gbs but the motherboard is listed at 3gbs. I'm guessing that 6gbs is SATA III and 3gbs is SATA II,...