Please let me know if I can be of any help to your future ventures. 

I spent a few years in the restaurant industry as well as other small business ventures while dabbling in real estate, but have just started getting serious about it.

Do not DIY this contract.

It is pretty easy to apply for here:IRS EINI start a new venture about 2-3 times a month and use this online tool.  

@Scott K...Trust me @James L was wrong for his title, but hey the guy is going off what he sees and hears on tv I venture to say.  

i've done joint venture money partners this way  Find a doctor who has liquid cash for full purchase price and repairs instead of going to a hard money loan lender A new LLC you create partners with the doctor for that one deal The doctor will buy it in his name and will contact you to do the work.Upon resell you will have an option to buy 50% of the net profits for one dollar The option will be secured against the property.  

I am 3 months into my first venture and inherited some bad tenants.

I tend to DIY everything the first time and afterwards determine I never want to DIY again.

I suggest being more specific as to describing the purpose and scope of operations, saying to do all things customary and then doing what you think may be customary can venture off into other tax code classifications of business, such as lending, and doing too much of another activity may put you in a different light and acting outside the scope of the primary mission.  

As such, "combining" funds in the manner you suggest becomes very difficult and even if done "in the recommended fashion" not without risk.There is an interpretation that an IRA/401k and disqualified party may joint venture in a very rigid fashion.The title is vested jointly on day one, reflecting the percentage of ownership.The equity in the project may not be altered in any way between the JV partners.AND - the tricky part - this is only OK if both sides could do the transaction alone and are not being enabled to participate in a transaction they would not have been able to without access to the disqualified funds.So, if your 401k (could) purchase a property - perhaps with a non-recourse loan - and chooses to JV with you instead, that is OK.