I went ahead and read a bit about your speakers, they sound like they are not especially hard to drive. In the Absolute Sound review they mention driving your speakers with an Air Tight ATM-1S a really nice tube amp from Japan. I owned the prior model the ATM-1 for about a year and quite liked it. Not sure your comfort level with tubes but I browsing the listings and saw this:
https://www.audiogon.com/listings/tube-a-reference-tube-amplifier-2018-01-06-amplifiers
That is the Air Tight ATM-2 the big brother of the amp mentioned in the review putting out 80 wpc more than enough to drive your speakers effortlessly. It also has two inputs, one of them with a volume control. Looks like a very reputable seller, I have no affiliation of any kind, and he's selling the amp for $5350, it's $15K new. You could use the amp with your P5 at least temporarily and you have $4650 of your budget It also gives you some flexibility with the volume control if you need to be without a preamp for any reason. Just one suggestion I thought might work as always YMMV. Good luck!
https://www.audiogon.com/listings/tube-a-reference-tube-amplifier-2018-01-06-amplifiers
That is the Air Tight ATM-2 the big brother of the amp mentioned in the review putting out 80 wpc more than enough to drive your speakers effortlessly. It also has two inputs, one of them with a volume control. Looks like a very reputable seller, I have no affiliation of any kind, and he's selling the amp for $5350, it's $15K new. You could use the amp with your P5 at least temporarily and you have $4650 of your budget It also gives you some flexibility with the volume control if you need to be without a preamp for any reason. Just one suggestion I thought might work as always YMMV. Good luck!