Good morning, Matt;
Back in the 1960s, I also wanted an Alpa 8d or 9d. It had this funny lumpy shape, but it was made where precision Swiss watches were made, and there was a likelihood that it also benefited from precision machining and workmanship. At least that is what a kid just out of school was reasoning at the time. I had to settle for a Minolta SR-1b, but I admit to having an appreciation for the Nippon Kogaku NIKON F. Now, 50 years later, I have the Minolta SR-1b (although not my original one--that is another story) and all of the other cameras in the Minolta SR Series, the SR-T Series, and a few in the X Series, although I seem to have specialized in the X-700 System there. And, I finally did get that NIKON F along with the F2 in a couple of variants and the Nikkormat/Nikomat also. Now I look at the Alpa 9d that I can afford now, but, as you have learned, finding lenses and accessories for them is a challenge now. When I also think about what is here now for the Minolta cameras, it is even more difficult to justify that 9d. Believe it or not, the urge or GAS can subside over a time period if there is the desired infusion of equipment to where you also notice that there is a lot of it around.
But, if that is the camera that produces in you a desire to feel the satisfaction there can be in just holding and working and looking through a camera that you really appreciate, then there may be enough justification right there alone to suggest that this is the camera you should have.
Perhaps the fact that not as many were produced has made a difference in how much people were willing to invest in the work to produce the third party books and publications that would have all of that information about the Alpa that you would like to see.