Historical values are easily provided; however, I would put very little merit to value projections. You need to analyze each property as being unique and consider supply and demand curves for that type of property specifically.
I generate these studies frequently for buildings or subneighborhoods of interest to investors, as well as for properties I am selling. William J. McBurney, Jr., Prudential Douglas Elliman, http://www.elliman.com/wjm - firstname.lastname@example.org
Mr. Hastings answered the question, Miller Samuels is the best. What I have said and he echoed in general, "if you are coming to Harlem there are deals out there, not steals." Also, you can check propertyshark.com and ACRIS websites.