Open Forum

We are looking for a software that will enable us to take reservations/ requests for group tours and programs. We have had one staff person doing this, but we have grown enough that we need to have a system that lets several different staff members have access to the same information in a common system.  Here is some more information:
   We are an Historic House site, open six days a week, for six hours a day.  We get about 10,000 visitors a year.  Half of our visitors stop in without reservations for the basic docent-led tour, and the other other half come for group tours and special programs that are booked in advance.  Some of our group tours involve catering (half of the busload goes on a tour while the other half has a meal in our education building, due to our capacity).  Our main contact database is Salesforce (non-profit service pack), and our webstore is based on Volusion.  Our current POS is Shopkeep.  A solution that works with any of those would be great, but we are open to a stand-alone program, too. 
    Does anyone have a recommendation or suggestion (or a warning about a program to avoid)?