Cummins Parts System For Little Guys?

Recently I had a fun adventure where I got bounced around to different stores, had to make several phone calls half an hour long, etc. to get a WATER PUMP for a 6B ENGINE on time because the customer needed it right away.

Every time I call Cummins for something large or small it turns into a fiasco but this was off the charts.

Are there online options for them and what might the costs be?

Cummins Parts System For Little Guys?