desktop speakers for low watt tube integrate

I think you would like a pair of ProAc 1sc's. You shouldn't have any trouble powering them with lower power tube amps.

The Reference 3A MM de Capo BE monitors would be a good choice & are very efficient at 92db/8 ohms. If space was particularly tight, the smaller Dulcet BE model could be the ticket; though note they are less efficient at 88db/6 ohm.

I would not be too concerned about efficiency if you are sitting that close to them, unless you tend to listen at very loud levels. Dulcet BE or KEF LS50 would be a safe bet for nearfield, and both are fairly small.

My biggest concern, should you go with multi-driver speakers, are that driver are too far apart to form coherent image at desktop distances. Small single driver loudspeakers, Omega Super 3 Desktop, for example, should eliminate concern & are probably better with low wpc SET. Consider Decware: Trapezium, also. Agree with Bigshutterbug largest concern shouldn't be sensitivity.

thanks, for the suggestion made by each one of you.

Being in Thailand, I don't have access to Omega and tekton, however it looks affordable and positive reviews.