CGIwire may be able to help you!
We have CubeCart, Magento, osCommerce, phpShop, Zen Cart and phpCOIN which can be setup from our auto installer within minutes!
Our "Power" plan may be suitable for your site as it has:
12,000 MB Disk Space
250,000 MB Bandwidth
Unmetered Mail Accounts
Unmetered Domains allowed (Pointed, parked, addon domains, redirects)
Free 0844 Number
If you have any problems, please feel free to contact us over at http://cgiwire.com
Thanks and have a nice day (:
After looking around, osCommerce allows item limitation
and also Zen Cart can limit items