I would agree with the recommendation of an HD7770. It's fairly low powered, so the power supply you have selected won't have any trouble running it. Also, at that resolution, I'm sure you could max out games easily with that card
Everything seems compatible, so nothing to worry about.
Do you think I'll break anything while transferring from my old PC to my new Chasis?
Yes I'm sure
Also, as long as you take your time to take your components out, I don't think you'll run into any issues transferring your computer to the new case! If you get stuck, you know where to come! There's lots of videos on web as well.