I owned the CODA CSib integrated amp and the KRELL K-300i integrated. Both are really good as others have stated. However, separates are better. I tried a lot of preamps (including the CODA 07x) with the KRELL Duo 175XD, CODA #8, CODA #16, and Benchmark AHB2 amps.
I found that the best combo for me was the Holo Audio Serene and Benchmark LA4/HPA4 preamps with any of the 4 amps listed above. An added bonus was that they were cheaper than most of the other choices I was considering. My choice was based on the preamp adding very little to the sound since the amps were so good.
Only caveat, I may not use either preamp with the SimAudio 860 V2. Not sure if that would work unless the speakers were a bit warm.