At this time, we were able to attract an offer on one of the units, not nearly as high as I would have liked, but still acceptable.

Most of the other groups tend to attract beginners.

I will definitely be in contact soon, what have you found to be the most effective marketing tactic to attract sellers in our area?

They are generally newer builds (usually built within the last 20 years), they come with higher end finishes that attract higher income earning tenants and low vacancy rates.

This attracts a broader variety of potential tenants of which to choose from.

If I dislike students and by extension the fast, yuppie singles, what can I do to attract families?

If you're looking to just get rid of the place as soon as possible, then selling as-is at an exceptionally low price to attract a cash buyer (e.g., an investor/rehabber) may be an option to consider.  

This will be my first rental property, what are the tenants rights, as far as the property changing ownership and the new landlord wanting to attract higher end tenants. 

If I were you I'd take care of the problem and have whoever treats the house look for anything that might be attracting mice (besides the rural location).

The numbers have been demonstrated ad infinitum; two of the factors that make real estate, especially buy & hold rentals, attractive vs. other forms of investment are leverage and permanency (the house stands 'forever', at least from the perspective of the investor's lifespan).