For starters, your host lests you SSH into the box? Change hosts.
SSH is a big security hole. It should never be allowed on shared (virtual) hosts. The only time you should be using ssh is if you own the whole server or VPS. None of the major hosts (e.g. 1&1 or godaddy or ) allow users to SSH in.
PHPnuke - this is old old old. It's also buggy and low in features. I don't understand why anyone would use it. Go for one of the easier to install, better features, and more up to date scripts that do the same job e.g. www.xoops.org or look at cmsmatrix.org to find a list of more CMS scripts. But phpnuke is a pain to install, hard to use, insecure, buggy, and out of date. You won't have this problem with most of the others as the script will install the database for you.
593kb is not too bit for phpmyadmin. The limit on php upload files is usually default to 2mb. You can check by running phpinfo()
As well as uploading, you can copy/paste into the sql command box in phpmyadmin. View the file in your text editor (notepad) and copy paste each block of code (e.g. one table at a time - though not one line at a time).