I have this bag and used it very effectively on my Daytona trip. I have the MP3 rack. (It's the one in my pic.)
Kuryakyn Gran Trailer Bag
http://www.kuryakyn.com/products/682/grantraveler-bag

This one is very popular also:
Aerostitch MotoFizz
http://www.aerostich.com/bags/seat-b...ags-large.html

Saw the Dowco Iron Rider bags on "Black Betty12" in another post on his MP3 rack - looked great.
https://dowcopowersports.com/motorcy...by/iron_rider/