Tethering two Saddle Tanks

[crakarjax]

I'd like to cut down from three to one filler tube. I currently have the stock tank and two dealer-installed saddle tanks. Does anyone know of a solid way to connect the two saddles so that I can just fill up with one?

On a related note, is there a benefit of going with a blazer tank instead of a saddle? I think the saddles are 20gallons. I ask because I can't think of a better place for my spare than under the bed.