Best Tube Based Options For B&W 803S Speakers

Thinking about taking the plunge into the tube arena to soften up the highs in my 803S speakers. I currently have an Anthem AVM30 using Genelec speakers in a 5.1 theatre system as well as an Anthem A2 pushing the 803S for 2 channel. I will be upgrading to a 7.1 processor at some point possibly the Marantz 8801 and considering an upgrade to the Oppo 105 as well.

My immediate concern is what would make the most sense and be cost effective in terms of trying out some tube equipment for a 2 channel rig. Perhaps keep the A2 and try a tube preamp, or sell it and try an integrated tube amp. Maybe try some type of tube based CD player using the analog bypass in the theatre processor. My budget is around $2,500 used and I am looking for something easy to maintain.

Comments are much appreciated thanks.