Now I have taken an addition line out on our house and wondering what is best with using this money for purchasing another property? 

If you can recouped your cost within 2 years with the additional rental income then the expense is justified.  

Additionally, the real estate company who sold it to me reached out and said they would be willing to buy it for 620k.

We feel like we can remodel and renovate the properties to bring in an additional $2,000/month(by turning one of the 1 bedrooms into a bi level three bedroom by taking advantage of the large pitched roof in each property.) 

Does anyone know any additional requirements?

These are professionals with additional training and a stricter code of ethics.

In addition to an accountant, you should consult an attorney on how to use your LLC to limit your personal liability which is really what it's for. 

If you think you’ll need to invest additional capital in them in the near future then you should make sure you know exactly where that money is coming from before you buy the property since your future employment is in question.The bank will look at your current financial situation, but they don’t typically inquire about your future state.  

Add it to your list now.As for suggestions as what to do.

Additionally once you find an agent or wholesaler to work with walk a few properties with them so you have stuff to compare to.