Support for the nic is just there. Throughput is based on a lot of factors. Buss speed, CPU, are you doing encryption... But on just about anything modern, you should get sustained 600 meg or so unless you are doing some strong encryption.
And I forgot. For nic vendor... Intel. Always Intel. Many problems with vlans, jumbo frames, or just heavy loading just go away if you use Intel.
Would an Intel Atom N280 have enough horsepower to perform reasonably well when paired with an Intel 10GbE NIC? I have a handful of HP Thin Clients (silent!) with x16 PCIe at my disposal. Also have Pentium Dual Core boxes, a couple of old Dell PowerEdge 2850s if the Thin clients aren't enough.