Space Hulk is for sale as a part of a compilation at
http://www.cdaccess.com/html/quick/eacomppj.htm - the price is $10, which for all those games is not very much.
However, Space Hulk 2 is nowhere to be found. HOTU has removed their download because Games Workshop has asked them to, but the game itself is unobtainable as far as I can see.