unless you have deep pockets it might be something to think about ...
i often times make dry plates with rocklands emulsions and they seem to work well for me at least as a negative or positive ( on glass metal or paper )
( and they gets faster and contrastier with age )
good luck with your search!
ps. making dry plates is an art form, not as easy as it seems .. you might want to practice on emulsion you aren't planning on using
before you commit to 500-600$ of commissioned emulsion ...