Looking for a Business Management System

I am from a pretty small sized, small engine sales service and parts business.

We are looking for a good computer system to handle parts ordering and pricing, sales orders, work orders, etc

Here are the top ones we have found:

• C Systems
• Ideal Computers
• Quickbooks POS

I was wondering if anyone has any first hand experience using these systems or was able to compare them.
Or any comments on the matter.

Thanks,
Lawnmower Guy