I wouldn't worry about HF absorption, since you can use room treatments, drapes, etc. for that purpose. I would focus on comfort. You should consider things like the length of your listening sessions since you may want more support and less cushioning if you sit for hours, and also what you do when listening, do you read, write, work on the computer, eat, drink, etc. Most speakers are designed for a normal range of seated ear height, so I would probably stay away from speakers that require your head to be at a precise level for them to sound good. Are you going to need a pair (or more) of these chairs to provide seating for your spouse or visitors? Personally, leather would be my first choice because it is cool in the summer and warm in the winter, and good leather is much more stain resistant and durable than fabric. Leather can be had economically, as I just picked up two leather chairs for our office entryway (at Furniture Row) for around $1K (for both). They are nothing special, but the leather seems durable and they are comfortable. My current favorite is a Stickley Eastwood Chair with leather pads on the seat and back. Next to that, my favorite chair was a fabric covered chair I purchased from Goodwill in college that appeared to be from the 50's. It was very sturdy, very comfortable, I could study in it for hours, and the arms were wide so you could sit a beer, books, and other stuff on them.