Hmmm. First of all I wouldn’t worry about biasing or remotes. If you’re going down this rabbit hole many meaningful options will include neither. Most of the suggestions here are good, but you will want to audition them. Many of the options mentioned are from firms that are out of business, so you can buy them cheap and likely resell them for what you paid for them. You will find something used in the $2k - $3k range that will complement your Merlins. Pay more and it will sound better, but you won’t get your money’s worth with the Merlins. The Ars Sonum Filarmonium (I have not heard it but I built and modified several ST-70s back in the day), would be a contender for me. I would also look at Rogue, Cary, Line Magnetic (along with the ones you narrowed down). Bottom line - you can’t tell unless you hear them in your system (or at least with your speakers).
That said, I would consider solid state amplification. You can get a lot more oomph to drive your speakers for less money than you would spend on tube amplification (and with a lot less bother). At the under $10k price range, I’ll bet SS sounds better too. Check out the Odyssey Cyclops. If you really need a tube to fiddle with, look at the Rogue Sphinx. You could burn your CDs, ditch the transport (nice piece of kit, but unnecessary today), and have several thousand dollars left over to buy music!
That said, I would consider solid state amplification. You can get a lot more oomph to drive your speakers for less money than you would spend on tube amplification (and with a lot less bother). At the under $10k price range, I’ll bet SS sounds better too. Check out the Odyssey Cyclops. If you really need a tube to fiddle with, look at the Rogue Sphinx. You could burn your CDs, ditch the transport (nice piece of kit, but unnecessary today), and have several thousand dollars left over to buy music!