Atheros GBE lan doesnt show

Thats not PCIe x1, thats PCI (old slot), this is not suitable for your mainboard, as it doesn't have PCI. You may use semthing like that :http://img.notebooksbilliger.de/ima...bit_CT_Desktop_Adapter_Bulk_EXPI9301CTBLK.jpg
But you have to check the compatibility to Proxmox first..
These works flawlessly with proxmox.

From my SuperMicro board (onboard though, but same chipset):
01:00.0 Ethernet controller: Intel Corporation 82574L Gigabit Network Connection
Subsystem: Super Micro Computer Inc Device 10d3
Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR+ FastB2B- DisINTx+
Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
--
Capabilities: [140 v1] Device Serial Number 00-25-90-ff-ff-ae-e9-ac
Kernel driver in use: e1000e

ethtool -i eth1
driver: e1000e
version: 3.1.0.2-NAPI
firmware-version: 2.1-3
bus-info: 0000:02:00.0
supports-statistics: yes
supports-test: yes
supports-eeprom-access: yes
supports-register-dump: yes
supports-priv-flags: no