http://www.undergroundhiphop.com
That site has all the songs I listed that are downloadable in RM. Quickest way to find them is to use the search engine they got on the site.
The Sound Quality is slighty abive avg at best for all of them. This site is truly the shit, freestyles, old school, instrumentals, radio channels, basically the Fort Knox of underground hip hop. The site even has mainstream rappers ( like Jay-Z) with a few songs that you won't find of his LPS.