Two or more subjects in personal statementWatch
surely internet computing & networking are quite similar, in which case you could write a PS relevant to both of them?
& there's no reason why you shouldn't apply for more than one subject.. i managed to get offers with my PS for medicine, history-neuroscience & history-psychology!
It's definatly best to apply for the courses you're most interested in, rather than make sure they are all the same. Even if courses have the same name, you may find the content of them is quite different and so it's best to apply for what you want to do rather than whatever makes writing a personal statment easiest.
I would write a general computing personal statement but say you are interested most in these two areas. You might find some more help on my website for Applying For Joint Degree and Applying For Different Subjects.