High power amps aren't the simplest creatures, especially tube designs. A 60 watt class A solid state amp is going to have something like 32V rails. A 60 watt tube amp is going to have rails more like 20 times that voltage.Our 60 watt tube amp kit has B+ rails of 150 volts.
It works well with Wilson Watt/Puppys, not sure about some of the newer Wilsons; most of them are fairly efficient, but lower impedance. So you can make the M-60 (kit) drive the Sashas quite nicely for example if you also use a set of ZEROs (www.zeroimpedance .com).
The amp is not hard to build but does take some time because each power tube only makes a few watts. You can see a video of one being built on our home page or on YouTube:
https://www.youtube.com/watch?v=yodVDiEIpqI