Thanks Balinor! I figured it out. I didn't make the border bold, but I cleaned it up so it seperates better to the eye.
In customer/main/products.tpl near the bottom, I commented the breaks out and
added <hr>. This removes the some of the white space and adds the light grey line between products.
Code:
</TD></TR>
</TABLE>
{*
*}<hr>
{/section}
Then about 1/2 way down in product.tpl, I commented out this line. That removes the light grey line just below the short description.
Code:
</FONT>
{*<HR size="1" noshade width="100%" align="left">*}
{if $products[product].product_type eq "C"}
Now the only lines are between products, so even though they are very light, it seperates and looks cleaner to me.