Hi jonnyleengo and welcome to WebmasterWorld.
Are saying there is only one page on your site or, only the index page has a PR7?
"Any recommendations for a conservative number of outbound links for my home page?"
Only link to pages of equal PR or higher from your index page. These links should be of value to the site visitors and of the same basic subject matter. (You asked for a conservative answer. PR7 is not easy to get)