Hi,
If you are wanting to switch the site to the root at any point in the future, I highly suggest you do not ever install it in a virtual directory. The reason for my recommendation is that the paths in your links, images and other items that require paths, will not work without directly modifying each one or manually updating every occurrence of the old path in the database. If you install your site in a sub-domain, you will not have these issues when moving the installation to another site's root.
HTH,
Joe D.