hmm i dunno... you could try making a switchless installer. but then you run into the problem of activating it.. i think you need a registration key to use the software?
then i guess after that, you have to figure out how to install the theme in the unattended cd and ALSO get the program to preload your theme...
well i found an addon for windowblinds, but it looks like you cant preactivate it . you might find more useful information in the thread
http://www.wincert.net/forum/index.php?showtopic=802