When the IT group insists on virus protection

What do I use? I'm the Lone Mac in a PC world. After a little over two years, we're going to move the MBP off the network, buy me a desktop PC and I'll have to move files back and forth with a USB and/or internet-based email. But having my own virus protection is required - and while I've searched and searched, I can't find the answers. What do you suggest?