you might want to check out nsis for an installer, its what i use for the installation of the eq2map updater, and is very customizeable, and FREE!
im just lazy, you can put custom images in it and such, just check it out at least since it wont cost you anything.
you can write all kinds of functions for it(if you want to, but you dont have to). an example is one day when i have some time i could add a check for if the .net framework 1.1 or greater is installed to end the "it wont start and give x135 error" threads in the support section for eq2map
http://nsis.sourceforge.net/
and then get HM NIS EDIT, which is a gui editor for it that makes it really easy to create the install scripts.
http://hmne.sourceforge.net/