stay clear of Oscommerce...
we run one site with it http://hardware.hk.com and it is a crock of shit to patch, upgrade and add stuff to unless you have got some seriousl PHP skills.
Maybe it has improved lately but I doubt it. The whole thing seems inherently flawed.
If you like the site hardware site, we have I will sell you a copy as it cost us a pile of cash to do. Clear the database, change the logo and add your products. Don't bother trying to do it from scratch.
In fact I could probably mirror the drive and then you have all the OS, libraries and pre-requisites configured.
I agree on the OSCommerce being tough to patch and the lack of a good module / plugin architecture.
BUT .. isnt Zencart a spinoff of OSCommerce?
I've been happy with X-Cart ... takes some amount of getting used to, but over the years I've found the russians pretty helpful if you're nice to them.
we run one site with it http://hardware.hk.com and it is a crock of shit to patch, upgrade and add stuff to unless you have got some seriousl PHP skills.
A bit messed up on your site, here's a page for a rack: