I\'ve had some trouble getting WiX projects to build on build servers. One of the pain points has been that my WiX projects are referencing libraries in c:\\program files
There is an unofficial nuget package at WiX.Toolset. However, note that this seems to only be applicable to the setup project itself (i.e. it cannot be used to fetch wix binaries for e.g. a class library assembly).
You can download just the WiX Binaries .zip from http://wixtoolset.org/releases/ then you can modify your wixproj file and update the <WixToolPath></WixToolPath>
element to point to your WixBinaries
The WiX documentation has an article that explains how: Integrating Wix Projects into your Daily Builds