My guess is that the Brokerage might object to this but I wonder if an escrow company might be able to collect the payments to the seller and pay the realtor on a monthly basis out of this money? 

I know that is objective of the forums etc., but yours just always appear to be given in manner that anyone can receive.

Below are some things you may wish to consider, as to which Corporate Enity is best, for your Business Model as well as your REI Goals and objectives.

What is your objection with those leads?

Not sure yet on the amount of renters in the Littleton area and if it is the right city to complete my objective.

My objective here is to buy the property, rehab what needs to be done, and then sell it.

I'd like to see what your objectives are and if we could be a match for you.

The key is to know your markets, know how to market, and be technically proficient in what you do, and that will go a long way towards overcoming any trivial objections.  

Then, when you don't agree to pre-release, they cancel and hold your funds hostage?

I don't think it was noted anywhere.Depending on the type, size, and your investment objectives, you could probably eliminate a lot of markets without doing much work.