While clearly I'm able to make concessions on this, I need a solution that can be configured to backup any folder I want and is not limited to documents folders (IE I would prefer to globally make a different folder in the profile handle the backup) with the flexibility to include additional pre-configured folders per department.
Outside of that, I want it to work with multiple OS's. Doesn't seem too complicated to me.
What existing products do you have in place to back up your server/datacenter?It sounds to me like some basic GPOs for folder redirection or mapping network drives to a file server would solve your problem for 80% of your network (I'm excluding the 15 macs and 15 pc's that you don't have joined to the domain).
I'm not trying to sound stubborn here, but there are reasons why the vast majority of the IT industry implements that type of infrastructure. You probably already have a file server being backed up to tape by some product (maybe Backup Exec), and your Windows servers and Active Directory already have all of the tools you need to get the data to go where you need it to go. There would be no additional software or licenses to buy. You might need to add some disk space to your File Server, but you're probably going to need to do that (or even add additional servers) to implement some third party solution.
For the other 20% of your workstations (15 Macs and 15 non-domain windows PCs), there might be additional licenses for your existing backup software that you can license to get that done. For example, if you're a Backup Exec shop, then you could look into the Desktop/Laptop Option. Most of the time you're already licensed to try before you buy on 5 machines.
I have no experience using the Desktop/Laptop option for backup exec, so I'm definitely not recommending it. I also don't know if they can backup macs.
Do yourself a favor and get all of the data you need to back up into the datacenter, and back it up how you do all of your other servers. Most organizations don't backup their workstations because they don't let end users store critical data on them.