My system is actually in my home office and consists of Wisdom Audio L8i in-wall speakers with a Wisdom Audio SCS-2 subwoofer.
the Wisdoms are 91db, 4 ohm. so a medium efficiency speaker. and if your system is in your home office, i’m assuming it is a ’bedroom’ sized room, maybe 15’ x 12’ x 9’? so you don’t need to power a big room.
most amplifiers will be powerful enough to get the job done in that room, so what i would recommend would be to focus on your sonic preferences. do you like a warmer sound? more transparent and neutral? what is your cup of tea? what music is most appealing to you?
reviewing a wide range of amplifier circuit technology is not going to be relevant to your situation. more telling us what you wish was better about your Luxman. as it’s a good amplifier already. and you have a subwoofer taking some of the load. where do you want to go?