Glenda, there is a new David's dress that has a similar cut. I've seen it in person and it is very pretty. Maybe you could find a seamstress to add the sleeves?
David's Bridal - Bridal Gowns P9345 Allover draped taffeta trumpet with button back.
I also did a search on their website for trumpet gowns and these were the results:
David's Bridal | Search
Here are Mermaid gowns:
David's Bridal | Search
There is always teh e-bay, craig's list, savethedress.com, etc route. Keep us posted!