I would definitely consider another dealer if you cannot demo these pieces in your system before purchase. Considering the amplifier can make a massive difference even at similar price points, I'd recommend trying a few at the same time so you can properly A/B them. Otherwise you'll always be wondering what else is out there. I honestly would not mess with a dealer that doesn't have demo products of what I'm trying to buy. Or has a very easy return policy...
On my amplifier journey I've tried 10 or so different amps throughout the last few years on both of my systems. The Pass Labs XA30.8 wound up being the keeper in my studio system. I have no experience with these amplifiers, but I do think T+A makes outstanding gear based on my experience with their DAC 200. I highly recommend anyone in this price bracket to try one before swapping other gear if you can afford it. Some dealers can get deals in the low $5000 range.
People who have these rigid %s they recommend for components seems kind of silly to me. There are values at different price tiers that make these types of assessments irrelevant. I recommend anyone with a solid system try a T+A DAC200 and tell me that it isn't worth the cost of entry if you're a primarily digital music listener. I do think going big $ on speakers always makes sense though because especially if you get large and heavy speakers, they're a big commitment and are harder to move and sell or to ship. So always make sure you're ultra happy with your speakers first, then the rest of your components will fall in line and your speakers should reveal all upstream component changes as you upgrade.
Let us know what you wind up with! Very curious on your thoughts on those amplifiers if you get to A/B.