Samster777, To keep the sound warm and non-fatiguing , you really need to address your entire system, including the room itself.
I have the same exact issue you have with my hearing and preferred sound. The main thing for me was to find the correct speaker , associated gear and cables that kept me in that comfort range. Treating my listening room also helped from keeping certain frequencies from getting out of hand and becoming bright , or harsh.
I think it might be a mistake to limit yourself on your amp of choice based on what will fit in your cabinet. I think you should find the right amp for you first, then change the cabinet if needed.