Yes, wire would most definitly help. Make sure it is light wieght though, otherwise your bow will droop. And that won't be very pretty.
You may even consider using fabric hardening glue, boning, or some kind of styrofoam to make a form for the bow.
As for the tails of the bow, you may want to make the bow you would usually make one, tie it the same way and taper of the tails. Make sure you're using a good amount of fabric though.
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