CRMs OTHER than Sage CRM integrated to Sage 100

SUGGESTED

A customer in early stages of implementing Sage 100 wants a CRM system.  Their (brand new) Sales Manager doesn't want to choose Sage CRM without looking at other CRM systems that integrate with 100.  I'm a newbie in this space so no idea if there are others that might suit him.  NOTE:  I have *no* idea why he doesn't want Sage's product, nor will he elaborate on what else he needs.  I'm just fishing for alternatives right now.