Mac OS X 10.6 includes QuickTime versions 10.0 and 7.6.3. The QuickTime 7 player will only be present if a QuickTime Pro key was present at the time of installation, or if specified as part of a custom install, or individually downloaded:
Snow Leopard update 10.6.4 included an update to 7.6.6 (if installed). You can install it from the above link even though it says for 10.6.3. It's the same version of QuickTime Player 7.6.6.
(Only QuickTime Player 7.6.3 or 7.6.6 can be updated to "Pro".)
As explained in http://support.apple.com/kb/HT3678, if you had a QuickTime 7 Pro registration code on your Mac before upgrading to Snow Leopard, QuickTime Player 7 should automatically have been installed in your Utilities folder & your registration code should still be honored.
But since QuickTime Player X is the default for opening most movie files, if you just open one by double-clicking on it, it opens in QT Player X instead of QT Player 7.
I get around this by keeping QT Player 7 in the Dock, & dropping files I want to open with it on its Dock icon. This works well for me because for most playback-only use QT Player X is superior, especially for HD content.