That's a very good article regarding the home equity line.

Some additional thoughts, when you are taking the home equity line of credit, you will have to pay off at a higher rate (prime rate plus a margin) as pointed out in the article.  It appears to be rational that you put the extra money on hand into your investment account.  Besides, it looks to me that it's rather expensive to establish and maintain the home equit line.

Read that article to begin with and lay out advantages and disadvantages, then you will come up with a better idea.