Here's the quick and dirty way to make your flippa listing stand out.
Find an auction that has a nice layout with custom text, bullet points and whatnot.
Right click - view source
Copy html from when the description text starts. Right after <h2>Description</h2> and copy from the first <p> all the way down to where you know the description text ends and the closing tags are. Will look like this </strong></p></div>
Now just go into your listing description and click the little html button, paste, and save.
From here you can add in your own details and voila you've got a custom looking listing.
Just REMEMBER, your site will sell for the most based on it's traffic, revenue, and the amount of trust the buyer has in you, so graphics, cool text, and flashing lights is no substitute! Just a way to liven things up.