If you are using a tube amp its mandatory to keep the speaker cables as short as possible- we've made 8" cables for our customers for this purpose (the amps our customers use on this speaker are monoblocks). It makes a big difference in the amp's ability to make bass on the speaker!
Its a good move you're getting the Yamaha power supplies refurbished. A speaker like this needs power and the power supply has to be up to snuff.
Pass Labs makes great amps for this speaker but since heat is a concern you'll want something class AB (your Yamaha is class AB) or else class D. The newer crop of class D amps can do quite well on this speaker. Your Oppo already has remote volume control. As remotes go, their solution was not too bad; Oppo had/has a lot of respect in the high end community- they were missed when they elected to get out of the sport.