The US-based server is obviously overloaded when it's slow and even gives 503 errors. The 404 error might be a permission problem.
When looking for Joomla hosting, always ask if the hoster is specialized in this field.
Some questions to ask:
- Do you run php in CGI mode (SuPHP or PHPExec) ?
this is important for security reasons (all files are 644 or 755) and you don't have any permission problems.
- register_globals: OFF
- Which version of PHP do they have installed (at the minimum it should be PHP 5, prefered is php 5.2 or higher)
- Safe Mode: OFF
You can find a few hosting companies here:
http://forum.joomla.org/viewtopic.php?t=6856Also, typ in Joomla Hosting in google and you get a lot of results. Good luck !