Your proposal is your first (and perhaps only) chance to make a good first impression to the freelancer!
Just as I though your the one who post this :)
if I have NO active projects now, I would have been making a demo for you :)
good luck,
please contact me in this email address in case this post will be closed and you have to find someone else.
blaisexen[]alt]google[dot]com
But I would like the business transaction would be here in freelancer :)