Should i resolve myself to add third party and ajax libraries that i use in my project - tinyMCE editor for example (more than 1800 files) or fckEditor - when my project doesn't contain nearly as many files, just for the sake of compilation? or should i just find a way to add it to the build later?
If the particular libraries have a public SVN repository, you can add them in as an svn:external - though I would add them in as particular known versions (on revision number or a tag/branch), rather than just the trunk.
Another alternative to that is SVN Vendor Branches, a more involved, but more power with it.