How about a retractable awning?
http://www.retractableawnings.com/gallferrara.htm
I think the architectural review committee will okay these, but you'd have to check. There is a distributor of sunsetter awnings in the Markets of Marion, on Route 27.
Otherwise, some sort of shade trees, you'd probably want to talk to a landscaper. I don't know about palms - they eventually grow tall, and might not be too shady. Of course, in the cooler winter months, you might not want the shade, because the sun would heat the porch for you. Maybe a shade tree like a crepe myrtle, that loses its leaves in the winter?
We have a west facing entryway and put in one of those koolaroo shades from Lowes. It keeps about 75% of the sun out which is a big improvement, but when the sun is really low in the sky, like right at sunset, you wish you had 100% sun protection. Our neighbors have the shades you described on their west facing lanai. When its in the 80's here, they've admitted they just can't use the lanai, its too hot, even with the shades down. But, they don't have any shade trees out back.
The awnings look really intriguing to me.