Integrated amp recommendations for Harbeth 30.1

I have a pair of Harbeth 30.1 speakers, with Exposure CD player, Rega TT and an MHDT Orchid dac driven by an iMac. I sold my Exposure integrated and want to find something a bit warmer and something that can tame edgy recordings. The room is difficult, roughly 19 x 19 but I use diy wall treatments to settle it down. I do want a preamp out option to drive a JL Audio sub at moderate levels. I do not listen to music extremely loud. The speakers are 85 dB efficiency. I am looking to buy used and am considering a Supernait 3, a Pass INT-30a and a Coda CSib v1. Others I would consider would be Luxman, Sugden, LFD, Hegel, etc. So looking for experience with these amps with Harbeth or similar speakers. I am hoping to stay around $4k. And I hope to find something that I hold on to for a long time and proves reliable. Thanks for your thoughts.