You know, you might just be able to use the P81 Enterprise textures on the saucer, because it looks good enough as is modelwise.
I have an example pic of this, but I'm at school right now so it'll have to wait.
IMO, the torps should be on the bottom dome of the saucer, since putting them on the lower engine wouldn't look right. But, maybe I'll figure out how to kitbash with M6 someday (after it quits crapping out on me
)
I"m sure Atra would let you, just as long as you give credit IIRC.