DWSIM supports database from ChemSep, CoolProp, Electrolytes and Biodiesel.
I wouldn't say that there are very few components... There are more than 600 compounds available right away, and you can now import compounds from web sources too. KDB database has more than 2000 compounds, and the ChEDL Thermo library has 1107 which can be imported to DWSIM. Not to mention the compound creator which you can use to create your own.