We won't be emailing any info as this is a public contest not something we will be doing privately with people to give advantages, etc. Any questions you have you need to ask here.
As far as byte size. We obviously don't have an exact size in mind
1k would be too small and 100k would be too big. You should know as a designer what is managable and what is not for a 120x60
There are no specific file size requirements or limitations on this one.