What else?

What else do you need? Nothing really, you should be up and running by now. But you may want to consider a...

Network card

Using a NIC (Network Interface Controller) directly under DOS isn't really recommended, as the drivers tend to take up a lot of memory (200-300 KB is not uncommon), leaving not enough for most games. It makes a bit more sense with a NIC under Windows (3.1+). Note that Windows 3.11 does NOT include network drivers on the installation disks, while 3.11 (Windows for Workgroups) does. It is possible to make it work under 3.1, using DOS-drivers.

But which cards can you find DOS/Win3.11-drivers for? That's the easy bit: Any card based on the Realtek 8139-chip! Okay,if you're a purist going for clean DOS, they are not period correct (as they are PCI), but they ARE dirt cheap, and Realtek themselves still have drivers online for just about every OS you can imagine.