If you do not want to upgrade to a newer version of ShopSite you just use the older version install. If your new host is a ShopSite partner they should be able to do that for you. If they are not a partner you would need to contact the ShopSite sales department for access information to the install files. You can use the form on
http://shopsite.com/ready-3.html to contact sales.
Note if you are moving from one partner to another or from a partner to a non-partner host you will need to get a new authorization file. If you were at a partner sited and had a monthly leased license and are moving to a non-partner site you will probably need to purchase a paidup one time license since monthly license are only allowed through partners.