The long arm should be able to handle the multiple fabric textures, but it would have to be free hand (hand guided). Pantos are often done from the back where the quilter can't see the quilt and might have problems where 2 uneven textures join. Same thing with a computer guided design it just goes and might get hung up on a thicker seam. Hand guided custom quilting will do the trick, but be prepared to pay extra. Sit down with your long armer when you drop off the quilt so everyone is on the same page.
As far as embellishments are concerned (buttons etc.) those go on after the quilting is done.