Hey Tiger,
Nashville huh!!!!!! I would guess (and I may be wrong) but country music? Anyway, there is a ton of books on this subject and all have variations of do's and dont's. My best advice on this may be:
Make sure your demo CD has been professionally tracked and mixed and engineered by someone who has clout!!!!! A good sounding CD will always outweigh the other sh** in your package!!!
Next, you said you have a way to send in solicited material, so who ever is doing this for you publisher, lawyer, manager etc;;;;;; should already have contacts that they are working with so you may not have to go crazy putting packages together..
Lastly, as far as blind submissions to labels I on't think anythings off the table, its a marketing thing so anything that makes you look big and/or promotes you in a positive way should be included