Spyware and Malware removal

[geekhelp4u]

Hey all, I am looking for some help on removing spyware and malware (in general, case by case instances) at the business level. I will lay out the software that requires a license. What i am looking for out of you guys is a free alternative or cheaper alternative for the software that requires a license... here we go

SpywareBlaster - Requires a License
SUPERAntiSpyware - Requires a License
MBam - Requires a License
Spybot S&D - Unknown???

I plan on using these tools (or similar) on a by machine basis. I want to install, run, clean, and uninstall. Thus a by machine license seems out of the question.

Do any of them allow licensing for unlimited machines - so long as it is only installed on one machine at a given time?

Does anyone know if anyone has a technician license, that grants an individual to use the software on a need basis?

Any other ideas or thoughts would be appreciated.

We currently only use Windows Defender as an anti-spy(mal)ware protection.
Anti-virus: Symantec
Firewall: Cisco Security Agent

Additional info that may help your thought process:

number of machine: aprox. 350
are all users admins on their machine: yes
location of machines: all over the world
type of company: technology outsourcing
number of service desk technicians: 3