Wilson Watt-Puppy Amplifier?

Really depends on what sound characteristics are most important to you.  Also, what’s your budget and are you looking for new or used?

The Audio Research LS28SE and VT 80SE. I helped a good friend that I helped put together a great system. He coupled Puppies with these ARC products. The sound is excellent and the warmth of the ARC components helped compliment the precision of the Wilson and calm down the treble. Sounds great. 

Roger Modjeski designed his Music Reference RM-200 specifically for low impedance loads. The amp resided in Stereophile’s Recommended Components List for a decade, and was Michael Fremer’s "affordable tube amp" for as long (and still is, I imagine). A Google search will lead you to his review of the amp (and the test bench measurements of John Atkinson, who was VERY impressed with the amp’s technical performance), both the original and MK.2 iterations.

The RM-200 delivers 100w/channel into 8, 4, and 1 ohm loads, from only a pair of KT-88’s each! Most tube amps are very unhappy with the load the WATT/Puppy presents it with (it’s very low at some frequencies). The RM-200 is a good choice for low impedance loads due to it’s far lower than normal (for a tube amp) output impedance (a/k/a high damping factor), it’s frequency response therefore far less effected by the impedance load of the loudspeaker than is typical with tube amps.