We are a small medical distributor based in Oxford PA moving to Philadelphia next month. We have a few employees. Our topology is attached. The servers are less than 2 years old except for the APPS/Domain Controller server which is two virtual servers- Apps, which we don't use and the DC to which all servers and PCs attach.
The project is to upgrade old Domain Controller hardware and software (Server2008) to new Domain Controller. The Domain has three servers (SAP B1, Portal Apps, Portal) and a handful of PC workstations (Customer Service x2, Shipping, Finance, Admin). The servers are on-site as well as the workstations.