There are 2 things I would change (putting priority on both) outright, if it was me:
I'd go with at least a 120gig SSD as my OS drive. My current gaming pc has a 240gig, and I have 3 or 4 of my favorite games on the OS drive. I do have a 400gig as my 2nd/backup drive, but it's something to consider.
For my "never skimp on this" suggestion.. I would not go with a Rosewill power supply, and I would also upgrade it to at least a 700watt PS. Something about Rosewill PS's doesn't sit right with me.. too many inferior parts can lead to a lot of problems. You would be surprised what problems a weak power supply can cause..and inferior power supplies can mask themselves so much that you'll be troubleshooting issues that look like something else. I've seen BSOD that looks like a video card issue, or memory problems, but come back to a weak power supply.
As for the ASRock motherboard, I've never owned one, so I would defer to others for experienced opinions. I'm a ASUS or Gigabyte guy, and have been for many years. However, most of the bios/UEFI settings are easily upgraded these days, and they can be upgraded via Windows if that is your OS (which you didn't mention).