The PSU will be an easy swap. Just make sure you have the right motherboard connection. The back I/O port board might pop out, but I can't seem to find a pic of the back. You could kinda sorta get away with leaving it open, since all cases come with an empty space there. However, the main hang up might be the mounting. The motherboard will most likely be an intel, so the cpu fan will need some clearance underneath of it. If you are going to go through with it, I'd recommend popping on a higher end CPU fan as well. Just read up on thermal paste and remember, THIS WILL VOID THE WARRANTY!
If you really wanted to get that plate out, you could also try to cut it out with a dremmel and maybe use a liquid weld to put it in the new case. But if you're going to get into that, why not just go full tilt and get a bare bones kit and build a rig yourself? It will cost more, but it can be a fun weekend project.