Based on several such jumps for ad shoots and one marriage proposal (attached)..you are wise to carefully consider how to rig the banner. it is not "just another skydive". A friend had one spin up rapidly on his hand as he let go to deploy and it was instantly a streamer firmly attached to his hand. For this reason, never use a loop of line to attach the banner. Here's how I do it:
...have the banner made of mesh material for light weight and less resistance, with extra binding tape across the bottom. I also have the message screen printed rather than vinyl letters which can roll up or blow off.
...Have 4 grommets spaced across the bottom
...Use lengths of wooden dowel attached with short lines as your handles.
...Use a felt marker on each dowel to indicate left hand, right hand and front of banner.
...I exit w/ both dowels in my left hand and the banner rolled up. As I approach the video (or future fiance) I unroll the fabric, glance at my dowels and place each in the proper hand and orientation. You don't want it to come out backwards.
...Once clear and ready to deploy, I put both dowels in my left hand and deploy normally.
...By using dowels instead of a loop I am able to move it from hand to hand, keep it under control and release it easily if I go to emergency procedures.
...Do not wear gloves or a top of the hand mounted altimeter.
...most of what I am suggesting is visible in the attached photo.
Consider the dive carefully, and make the banner minimum size. 4-5 feet is very long and can cause issues with floating up in the center. Dowels help with this as well.
Have fun and send us a picture.