Many sellers will not accept this since they are in second position, and it is very risky since if you default (higher probability for investors with no money and/or no skin in the game), they will most likely be wiped out during a foreclosure.

I still am on the lists of all the major wholesalers and still show up to showings occasionally on properties that might have enough margin for me but have not purchased recently from a wholesaler.Just like Adrien says, they provide a service of marketing and negotiating contracts for you.

Each housing authority (HA) provides a voucher amount determined by bedroom and some further define it by zip code or city within their covered area.

This means you need to pad your rehab costs, make sure you have trusted service providers that do great work, and when you run comps be sure to bring them down a bit and see if the deal still makes sense. 

Our state licensing department provides the list of licensees for free upon request. 

Or suggestions for other companies that provide a similar service?

Have also used list source and prop stream before but the data they provide is very similar to what I pull off the tax records through CRS Tax. 

The value of the info he provided cannot be understated.Residential RE is more challenging then a few years ago, but there are a lot of ways to make money in RE.  

I think it is really up to what you can provide to the investor.

Why not test the market by putting the lots up for sale, and if nobody bites, that might provide your answer.