Look, first of all the 2 ohm load is more than likely in a very narrow frequency range. I don't know of any speakers that are nominally rated at 2 ohms. Secondly, the sensitivity (efficiency, if you like) is another consideration. Thirdly, the phase angle of a speaker should be another consideration. Some other posts mention room acoustics, etc. So it seems it is not such a simple answer.
Of course, you could always by some brute force amp and probably not concern yourself.
My own experience is using 60w tube amps to drive Acoustats and Magnapans to very satisfying levels.
The speaker mfg certainly could suggest the best type of amp, but any good amp that is rated for 4 ohm loads will probably work just fine.
Jim