Before I bought JM Lab Mini Utopias, I listened extensively to the Micro Utopias, DeCapos, and the small, top of the line SFs at that time - Im sorry, I cant recall the model designation. I preferred the Micros by a considerable margin but I know others who prefer the SFs. All three are good speakers with the Micros and SFs clearly outclassing the DeCapos IMO. You have to get everything upstream right for the Utopias to shine, in my experience. In your small room, all three of your amps - even the EAR - might work; although I wouldnt recommend trying a 15W amp if you didnt already own it.
Are you familiar with Sonus Fabers service policy for speakers not purchased from an authorized dealer - its absolutely dreadful IMO. Sonus Faber thread
Are you familiar with Sonus Fabers service policy for speakers not purchased from an authorized dealer - its absolutely dreadful IMO. Sonus Faber thread