Atmasphere is right regarding ss amps with the Coincident speakers, they can/will sound good but with a quality tube amp good is elevated to a range of very good/great.
SS amps can/will sound good?...not necessarily IMO, nor necessarily will any tube amp be ideal IMO. When I spoke with him a few years ago Israel told me he used several different amps, to voice his speakers, including his own, of course. Regardless, I'm sure users will find there are those that do not pair off as well as others, and certainly did not mean to suggest that high-powered SS is the way to go - it's simply what I chose and what sounded best for me (my music, my room, my ears). The two that worked really well to my ears were the KWA150's I use, and the Ayre VX5e. Both are outstanding with the SE III's in every respect, and I would not hesitate recommending either (and I normally prefer tubes, or have for over ten years). My direct experience is relatively limited; I've only tried a few amps over the two years I've had my SEIII's, of the tube amps there were Quicksilver 300B SET's and Mini-Mites, VTL450's, and Cary SLA-70's. SS amps I've tried have been the Ayre V5XE, Bel Canto 1000's, Odyssey Stratos Dual Mono, and Modwright KWA150's. Of all of those, including the tube options, the Ayre and Modwright were my personal favorite combination, followed closely by the 300B's. None of the other combinations floated my boat quite the same. The best advice I can think to give is try them out yourself and see what works for you. Clearly no one can tell you what you will actually prefer when you put these speakers into your system in your room, and listen to your music with your own set of personal preferences. My experience has been that the speakers are very versatile and can work well with a wide variety of amps.