Fabric banner material
I don't know who you talked to at Fellers, but they must be new. They carry Magic's FAB-6 flag fabric. It is supposed to be able to be used in and out of doors. It is a 6 mil polyester that is pretty opaque. I have used it a number of times to do table drapes for tradeshow tables using HP UV ink. One nice thing about it is that you can buy a 36"x10' roll if you think this may be a one time thing and you are not stuck with another 90' that you don't know what to do with. If you do a second and hang it up in the shop though, I think you will find that most people really like the fabric banner and will try to find a use for one.
I have also used 3P Inkjet's "Heavy Express Banner". It is also a polyester, but is a looser, coarser weave and you can see thru it a little. Looks really good in verticle banner stands and can be used with all inks. There are a whole bunch of people making banner fabrics out there and they are all a bit different. Once you know more what your customer is looking to do with the banner, you can start to see what looks like it is going to work the best. I have gotten some samples from Fisher and they look nice, but they are pricey. Don't quote a price until you have a good idea what you are going to be using cause there's a big price difference between poly and silk.
Good luck
