Small Footprint SS Power Amps

“14" or less wide.”

The dimension limitations regarding depth and height would be of use in providing you, The Original Poster, accurate recommendations. 

Adcom GFA-1A, Belles II, Carver The Cube, Quad 303 and 405, SWTP 207. All narrower designs. I have them in my amp collection.

AGD Audion GaN monoblocks. 

Quad 405 or 405-2.  100 watt per channel current dumping power amp.  13-3/8" wide by 7-3/4" deep by 4-1/4" high.  The heat sink is in the front so side ventilation is not an issue.  With a Dada Electronics revision kit and Dada's DC protection/delay modules, you'll have a very fine SS amp. with the power and size requirements you are after.

+1 hypoman! The Quad 405 -1 and 2 are great and innovative SS amp designs worthy of inclusion in any hi-end system! Too bad that today they are largely forgotten due to the hype for the latest greatest amp! Mine has been nicely upgraded by the previous owner.