For what it's worth, if customers are making this shift, we have a custom distribution system built from the ground up in SageCRM. The advantage is that using Sage CRM for your front office (instead of moving to a traditional ERP like MAS or Accpac) allows you all the bells and whistles and ease of customization that CRM offers.
It handles Inventory Management, Asset Management, Sales, Purchasing, Servicing and Accounting Integration. I've only sold a handful but am steadily ramping up that side of my business.