Is your company aware of OpenACS? Have they consider using OpenACS's ecommerce package? It contains bug fixes and is a direct evolution of the ecommerce package from ACS 3.4.10, if I'm not incorrect.
There are sizeable issues involved in upgrading from ACS 3.4.10, but if you're installing new services, there might be some reason to use OpenACS, especially since you have other programmers who will be contributing to your code-base.