That boards a bit of an odd duck. USB3.0 and low end everything else... but I digress. You can run any SSD you want. they are just drives and SATA is fully backwards compatible. You only have 3Gb/s SATA ports though which will limit the Max speed to around 350MB/s. Sequential read/write isn't the big issue though, random is and most drives still wont hit that limit.
1. You can use any SSD. even if it says it is SATA III or 6Gb/s you can still use it.
2. Just because it says SATA III/6Gb/s does not mean its faster than a SATA II/3Gb/s drive. that is just the interface. You need to look at actual read/write speeds
3. You'll probably want a mid range drive as your ports would limit the very high end(expensive) drives in some circumstances.