I'm a fan of Zen cart... Not that its exactly easy to navigate, but it does make significant upgrades to OSCommerce.

Only that implementing Zen Cart into an existing design is nearly impossible based on the budget for this project... It would take me forever!

Are there any shopping cart softwares out there that are easy to plug into an exisiting design? Don't have to be too fancy... I'll take care of that part.

Any ideas are appreciated greatly.