10G is directly supported by Kintex transceivers (TRAP ALERT - watch out for right package/speed grade combination!).
On a PHY side, take a look at VSC8491 chip from Microsemi, or VSC8489 for dual-10G PHY. Hint - since Microsemi has been acquired by Microchip, search for that chip on Microchip's site instead of Microsemi's one - this way you can download full datasheets without any of Microsemi's registration crap.