It is very possible you can add a rental to your personal lines package policy for very little. 

The best way to find out is to submit a completed package to the lender.

BP,I am possibly purchasing an off market package deal with 4 different properties in Chicago.

From the info you've provided Id say you need either a dwelling-fire policy (also called, landlord policies) per property, or a commercial package policy to put all 5 properties on one policy.

Portfolio lenders will keep the loans in house instead of the typical bank that packages several loans and sells them.

If she does have her license, than the SOW and the sell of the property should all be packaged and presented to you as a proposal for your sign-off. 

Anyone know of any banks/lenders/mortgage broker who would do a package financing deal of sub $50k SFR (4-5 properties) in MO for buy and hold?

Has package of 11 properties in historic northeast that are all occupied, and have had long term tenants in place. 

And in terms of content, do you mean just change it up a bit and change the packaging of the letters?

Ask the listing broker for the marketing package and use that as your template.