I would not think most brokers would care (Although I could be wrong) as long as they get their piece of it.

Once piece of advice, just buy their raw csv data for the past 12 months sort it yourself so it's usable/meaningful.  

The basic scenario runs like this:  seller gets a marketing piece, or goes to your website, or whatever, then speaks to you after passing through all the hoops set up to weed out the unmotivated.  

I feel like I'm missing some piece of the puzzle, but I just don't know what it is.

Unless you are well capitalized and don't need participation from lenders, then seed capital is the critical piece of the equation to get things going. 

I already have my list of subs and suppliers that I've dealt with for years, so the construction piece is taken care of.  

I also purchased a few pieces of land through a tax deed sale, using profits to purchase a 4-plex I held for a couple years.

I'm not sure how often other investors mail out pieces but I like to take a two step approach.

When I hear some of the stories told by other REI (via- BP/Blogs/Forums) I feel like bits and pieces are missing if not chunks of information are left out. 

The house was a foreclosure in bad shape; the cabinets were missing a drawer, a face, and one small piece of trim.