"Currently we store our accounts data on a mapped Samba drive, Sage support told me I need to use a windows server or it wont work!"
Sage is stuck in the mentality that the "Server" is the main accountant's PC and that the "clients" are everyone else. Administrative account? Why would you want that? The main accountant handles all the administrative stuff, right?
Just make sure all of your clients have the same file mapping. Ugly file locking gremlins can pop if if one client attaches using "\\sageserver\sageshare\mycompany" and another attaches using "F:\\mycompany".