The consensus seems to be you can use full size cat 1 implements. Although sometimes you need to move the pins on the lower attachment point of the implement to the inside of the mounts. This is to allow for the narrow space between the rear tires. The other possible difficulty is lifting height, this is also not what is usually found on a cat 1 tractor. I believe the height is a concern occasionally with items like a post hole digger.
This is the reason I like the sub compact specific implements, they take these into consideration as well as weight, which is also a concern.
I am not sure I would want a 5' grader box. Unless your just moving gravel, or loose dirt. I have a 4' and for grading firm ground, it is about all my 2310 can handle.