I need to transfer large number of products from wp ecommerce plugin into new theme

industryclub.com.au has a 1043 products set up in wp e-commerce which I need to transfer into a new site which is compatible with woocommerce.
I have exported the products into xml file (143Mb) but import fails with a memory error:
Fatal error: Allowed memory size of 268435456 bytes exhausted (tried to allocate 72 bytes) in /home/industry/public_html/wp/wp-content/plugins/wordpress-importer/parsers.php on line 194 ...
php.ini has been edited to allow 256Mb
The second part of the question is how do I convert the imported products to a custom post type/