Mac mini server capabilities

Looking to go server in my wife's dental office. We use MacPractice DDS and love the software. It can run in a pier to pier arrangement, but the developer keeps pushing us to go server. The problem is that the company rep wants me to drop some serious money on a MacPro server setup. I was looking for feedback from people using the mini server in an office environment, specifically running practice management types of software. If someone is a healthcare professional running MacPractice dds, md, od, etc, I would really like to hear from you guys on how the mini server is working for you. For all you Apple server gurus out there some information on what kind of files our office handles. MacPractice is a sql based product. The database file also contains large amounts of attachments such as jpgs from digital x-rays and interoral camera photography. We also have extensive amounts of pdfs that are associated with patient records. Currently we have 7 macs running the software in pier to pier configuration. Ultimately when all ops are outfitted we will have 12 mac workstations and this is why MacPractice is pushing a dedicated server environment.

Any input is appreciated.