There also may not be advantages as compared to your self-directed IRA, depending on your situation and goals.Either way, you can likely consolidate the existing SDIRA and new rollover funds into either the existing IRA or a new Solo 401k.  

The idea is to consolidate our resources to buy a rental property whenever we have saved enough for a down payment.

(Believe me we charge extra for that behavior)Here is some information that has been compiled here and a link to a thread I helped consolidate a ton of questions to ask.You definitely need someone qualified, does not have to be a CPA, could be an Enrolled Agent or an attorney.

It's paid off, appraised at $958K, took out a $300k HELOC to use for consumer debt consolidation, cash flow $2750 per month.

It just consolidates the liens for multiple properties into one note but can sometimes be done in an LLC name rather than a personal note.

If you do a refi and let it sit in your account you are paying on money you aren't using.Oh yeah, in case you are wondering why I'm doing a cash out refi, I'm consolidating 3 notes into 1.  

I'm not a tax guy and my circumstances were different, several companies consolidate where one was not showing a profit, so the allocations of expenses were more flexible.

Besides credit issues with buyers, in a lease-option this is the number one reason such consolidated lease-option agreements fall through, insufficient down payment.

I think pulling everything together into one website would be useful in my mind... but I don't know how feasible this might be...One site which consolidates MLS listings (redfin.com, zillow.com), demographic data like distribution of family size, rental unit composition (city-data.com) rental comps for closed leases (rent-ometer.com, zillow.com), on-market rentals nearby (CL), walkscore/bikescore/transitscore (walkscore.com), etc...Of course, right now, these all have their proprietary models.. maybe you can just throw them a few pennies to aggregate it, or justify that the aggregated information is your own product..

I pulled $66k out to consolidate $26k in unsecured debt and to put down payment on a Tri plex in next county over with an off market deal