The Moniter Audio speakers appear to be a bit more tube friendly based simply on the nominal impedance. If you want truly tube friendly speakers that will work on a variety of tube amps (from the lowest power to higher power amps) I would suggest you consider the speakers offered by Audio Note. They come in three basic sizes; each size is available in different cabinet finishes and different levels of components/build quality.
If you hear a pair of Audio Note ANJK/L or ANESp speakers you might be quite surprised at how good they sound. All three are a basic two way design with a minimalist crossover. The key is matching of components carefully and the quality of the components. The more expensive models use silver wiring, Alnico drivers, and sound materially better than the entry models. The entry models sound fine, too; I am on my second pair having used a J and now a K (due to space limitations).
All three of the speakers will work fine with 8 watts of good single ended tube power.
If you hear a pair of Audio Note ANJK/L or ANESp speakers you might be quite surprised at how good they sound. All three are a basic two way design with a minimalist crossover. The key is matching of components carefully and the quality of the components. The more expensive models use silver wiring, Alnico drivers, and sound materially better than the entry models. The entry models sound fine, too; I am on my second pair having used a J and now a K (due to space limitations).
All three of the speakers will work fine with 8 watts of good single ended tube power.