I believe Kings Quest and Police Quest were both recently re-released here. Not sure if you would find them down your way though.
Up here Future Shop (standard electronics / games store) was selling them. As far as playing, I think at least XP compatible (just a simple port of some form I think)
From the Kings Quest Wiki...
"In September 2006 Vivendi Universal released King's Quest Collection
, a compilation CD for Windows XP encompassing games I-VII. Rather than porting the games directly, however, the release used the original, unmodified versions run under the DosBox
emulator and a Windows frontend. As a result, it is also possible to run King's Quest I-VI on other platforms with a little tweaking and ports of DosBox versions .63-.65. (King's Quest VII is run natively under Windows, and compatibility was broken under DosBox .70.)"
Police Quest & Space Quest both have similar comments. Nothing on the Quest for Glory series though...