[UX] Maximum upload size should be an integer element

Right now the maximum upload size is a text field and we need to provide a very lengthy explanation about how to use this field... Enter a value like "512" (bytes), "80 KB" (kilobytes) or "50 MB" (megabytes) in order to restrict the allowed file size. If left empty the file sizes will be limited only by PHP's maximum post and file upload sizes (current limit 32 MB).

Is there a cleaner way to do this? Perhaps two fields, one an integer, the other a set of three radios for bytes, KB (kilobytes), or MB (megabytes). Thinking further, is the bytes option really necessary? We are talking about the Maximum upload size here...