I could be really mistaken, but I doubt you'll find any non-medium format (and maybe not even then) digital that will shoot 300ppi (pixels per inch) out of the camera.
At it's highest resolution the Canon 10D for instance is dumping jpgs at 180 ppi.
Now if you use something like PS Ce or Capture one you can convert the raw files directly into a 300ppi image. Otherwise you just make sure you shoot at the camera's most detailed file size, depending on the camera it could potentially create a file that's like 180 ppi and would print out at say 16x24 (as an example,) if you go into PS you can then use the image size menu to resize the image (pixel wise) increase the ppi and keep the same print size. Or alter it to fit your output.
It's all kind of messy. It also gets worse when you throw in dpi which is dots per inch and in fact is a rating of how many ink dots the printer is putting out. Most (all? I'm not 100% sure) printers today don't read more than 300-330 ppi but can print to a substantially higher dpi.
The two cameras you've choosen get good reviews on
DP Review (one of my favorite digital info sites) so I doubt you'll go wrong with either. You may want to make whom ever has to send the photos out, (unless it's you of course) aware that getting a 300ppi image is part of the post camera process.
Dave