as this watch is normally off the radar screen for people thinking of their 1st Panerai. Personally I love the watch. It's the only panerai that I sold and subsequently bought back! Although there're elements that I don't prefer, such as the cyclop, it's still a very wicked piece and I luv mine!
Now onto your next: do you really want to blow $20k all onto one watch? How'bout a 249 then a 372? From strictly asthetic's perspective, you will have two of the best dial representations from Panerai which really defines the DNA of the brand.
The other alternatives is to dig a little deeper. As you already mentioned, a 322, IMHO, is the perfect example of historical lineage w/ fantastic movement finishing.
As others mentioned, there are really no boundaries but I would be VERY careful in terms of venturing into pre-vendome/vintages. Given the potential amount involved, it might not be a bad idea to see if your new-found infectuation is here to say or not. Good luck!