I was offered a deal to do a joint venture on one of the houses that needs a little work ($7-10k).

I was a Licensed Mortgage Broker back in 2005-2009  and flipped a few homes when no real skill was needed back then and made good money which I foolishly invested into a joint business venture with my hubby in 2006.  

You might want to consider a Joint Venture with an experienced note investor, as they can show you the ropes, and you get a note that you split profits on, vs paying for expensive training. 

There are many people willing to Joint Venture on a project that may be willing to partner with you and provide the cash for a percentage of the profit.

If I set up a series LLC with my wife do I have to include the equity partners as part of that LLC or can I just have a joint venture agreement set up for each property.  

It's called a JV (Joint Venture) agreement and people do it all the time.  

You could get an FHA loan of 3.5% down (you can put that on a credit card or line or credit).You could do a joint venture with someone who has money.

Long term capital gains for income up to 75,300 for married filing jointly is completely tax free. 

In short, the funds need to be separate, but you can jointly own property in both SDIRAs through Tenancy in Common.

This property is jointly held.