So I was wondering if msi motherboards are good or they are bad for overclocking (z97) compared to asus
MSI and Gigabyte both make good mobos. I still like Asus the most, though.
are they good overclockers aswell?
Yup. You can easily get the same overclocks from Gigabyte or MSI boards. It's just particularly easy on Asus mobos.
ASUS is generally considered best, but MSI and Gigabyte are good budget alternatives, and are by no means bad. I have no experience with ASRock, though, so I can't tell you how good they are.
Yes, mostly, but it depends on the individual board. The MSI Z97 PC mate is pretty bad, but some of their mid-range offerings are pretty good, like the G55 SLI board. Gigabyte's GA-Z97X-SLI is a good board that's super cheap right now, and will overclock fairly well.