The Virtue OLED board for the Etek2 will actually fit the AM frame already - you'd just need some different grips. The Etek2 OLED grips would actually stretch to fit the Etek3 frame, but you are increasing the likelihood that the grips would split at some point in the future.
As to whether the Emortal board is worth while is entirely down to whether it provides you with the features you need or not. It is a great board, but it is expensive, and is limited in some respects when compared to an after market board. For instance, like the stock board, it is limited to semi and ramping - there's no NXL mode and no recreational modes. It does however have the LCD (of course), a game timer, rate of fire counters, a shot counter, battery meter, allows for higher rate of fire caps (22bps) or uncapped ramping, has tournament presets, has two user profiles to save your settings (and you can have a third group of settings in use) and has additional adjustments available.
If all you use is semi and ramping, then it is a good board. If you want additional modes, or are interested in the Virtue board's training drills, then obviously you would prefer the Virtue.