Actually, for you your first, either just an Uno or get the Uno and Mega.
http://www.dealextreme.com/p/arduino-uno-rev3-development-board-120464?item=14
There are infinitely more projects that are turnkey for an Uno that take a bit more work for the Mega. Only the UAV community and HTML users use the Mega to any degree.
That said. I got the one with the 16u2 since that is closest to the Mega2560 R3 (Still missing the SDA SCL pins). I could not tell if the other was a 8u2 or 16u2. But that using of the crystal instead of the resonator is intriguing. The Uno R3 clone looks real good and even has the extra SDA SCL pins.