I ran into a similar problem with my shaper, I needed a fence to run my boards against while running the shaper because not all of my bits have a bearing on them. I ended up coming up with a fence that resembled a Biesemeyer Style, with a cam lock and t-shape. I made a video of it on YouTube, you might want to check it out. You said you have a portable contractor saw, you might have to be creative to get a mounting for it. Mine just had holes drilled into the casting so it was pretty easily accessible.

Here's the link: