Separate or parent LLCs for Flip business and Contracting busines

[Tracey Hamilton]

My husband and I have an LLC for our general contracting company, whose sole client will be our flip business. I am thinking we need a separate LLC for the flip business, but should the flip business be the full owner or an LLC member of the contracting business, or should they both be separate businesses, and we just are the owners of each one?

And to make it more fun, I just got my real estate brokers license, and am currently set up as a sole proprietor with my brokerage.  Will there be any big drawbacks to leaving that as-is, besides self employment tax on any commissions?  

My head is starting to spin a little with all the different entities.  Thanks!