Why do you want a portal page? Most successful online stores drop the customer directly in. There is no need for index.html, home.php or any other variant.
This means simplifying your path to root and putting your store in the root. There is only one way in:
www.roadrashapparel.com
That's it... no other URLs to think about, worry about, deal with or fix.
Unless your business is not about selling things and the xcart store is an add-on, it would take some serious justification to argue for a portal page.
There are many, many threads up here discussing this.
Try a search for "install to root" or "portal" or "landing page" etc...
As Paul suggested, a simple line in .htaccess will do this for you - but you have to want to lose all the variations... put your store in root (get rid of the /xcart/ in the path) and you will simplify your life.
My $.02