FXS for mini-pcie

Hello everyone,

Currently I’m running Asterisk on a netgear router, which is basically fine, only the speed for the USB attached harddrive could be faster…

This is why I want to build a small Atom (N2600) based server, which will run ASterrisk, OpenVPN, FTP, Samba,…
As I don’t need WiFi I have an additional Mini-PCIe slot empty, which made me think, if I should use it to connect an analoge phone to the router, which would mean that I could even get rid of my ATA.

So far I only found PCI, or Mini-PCI FXS cards, and one really expensive PCIe FXS card. Does anybody have an idea, where I could find one for Mini-PCIe? Or, but this is probably a stupid one, if there’s another way to connect a phone to the computer? The board would still have 4 empty serial ports for example!? (Or USB)

Any hints or help is greatly appreciated!