I've never read the Dave Lindahl stuff...sounds sketchy though. When you buy a single family home, a duplex, triplex or a fourplex, this is legally viewed by lenders as residential property. You can gain more leverage in residental property (usually) because the lender views it as less risky.
When you buy more than five single family dwellings on one parcel, you switch to commercial paper. It's a different game because the laws are different. So the lender often times will ask for at least 30% down. You might be able to network with other investors and form an LLP or get a seller carryback, but I suspect that a lender would want to see some serious experience as a real estate investor.
I have not purchased Mr. Lindahl’s courses, but I have heard him speak. As with all gurus, he appears to be long on hype and short on accurate details. For example, very few gurus tell the real story of landlording: the poor quality of tenants, the drug dealers, the drunks, the evictions, the constant stupidity that must be dealt with. They also don’t discuss anything more than the most obvious expenses. The focus of most “gurus” is to seperate newbies from their money, not to provide the best possible info. I’m not saying that the info is not good, but it is rarely complete. The reason for this is that the gurus are always upselling you to their next higher level where the secret to REI will certainly be revealed.
In my opinion, you’d be better served by reading a few books and joining your local REIA. Become friends with real (successful) investors and get to know your market. Look at websites for professional organizations such as the National Apartment Association.