As good as they look, your faxes are liable to be read by a computer first. This means that you need to limit yourself to widely recognized fonts and to keep your material no smaller than 12 points . Widely recognized fonts include Times and Helvetica. But, if you are going to use either, make sure that you know exactly what the output looks like on the other end. Send a couple of copies and make sure that you're happy with the results.
Email is a different matter.
The only way to control the look of emailed resumes and cover letters is by limiting yourself to no more than 50 characters per line. Recent estimates are that you will spend somewhere between 6 weeks and 6 months finding your next position. This means that Rejection will be your constant companion. Try to imagine that you are a product in the hands of a direct marketing firm. With those percentages in mind you can expect one or two responses for every 100 resumes you send out.