I have a slightly different strategy for this.
I've hand picked blocks at Chicago, from Mimmo, Manno and Makis. And had winners and losers from that experience. Like, you can get a XX grade plateau that just isn't very clean and won't make a smooth from ANYone! And hell, you can pick it yourself which is even more frustrating!
I've thrown out Mimmo Grade 1 blocks. I've thrown out Jaume's super-grade. I've thrown out Makis's tightest hand select. And conversely, I've gotten great, great pipes out of blocks from eBay, from #2 grade stuff from Mimmo... like, it takes awhile to match up material, shape, and skill level (and the luck that the briar holds).
This is a Mimmo 2.
I'm sorry, but that's good enough.
It wasn't hand selected, it came in a batch I probably got either direct from Mimmo or from Steve at VermontFreehand - more likely the latter actually. The point is, I don't know. It was here. With the blocks. Piles of em.
This isn't an "everyday" thing, you don't just walk into the shop and bang out perfect grained straights (this was a commissioned sandblast btw - the customer still teases me about being too lazy to blast it). They happen. To make them happen more often, you need ..... a lot of briar. Big ones. Little ones. Wide ones. Crooked shit. Long ones... fat, short, twisted... all of em. You can't just have 3 blocks on hand that you know are somehow pre-ordained for greatness. They aren't. They can all fail. They can all have that funny run in them, they can have a rock in the middle. They can stain weird, they can be ugly in 100 ways. What you want is 50 blocks to pick from, and then you can knock out pretty nice stuff pretty often.
Can you spot the eBay briar?
This is not about having some magical source for only perfect blocks because all you make is super high grade pipes. Or, if it is, you already have this source because you've been at this for 20 years. (In other words, "Hey New Guy, you're order of 5 mediums isn't a bulk order!" (and I'm not directing that sentiment at the OP, just there are lots of people who are surprised that cutters/vendors won't accommodate the totally unreasonably demands of the guy who is going to make 3 pipes and then quit) ).
The other side of my answer is, "Relationships."
Build them. With pipe makers, with suppliers, with everyone. Pipe making is still a small group. Eventually, you see the same people again. And again. And if you fucked them in the past, you won't get the big smiles.
Somewhere on this board is a post by a guy who bought 50 blocks from a greek vendor on eBay. This is years and years ago. He thought it was a good deal, and he pressed "buy it now" again. And the shipping.... didn't change. So he did it again, and once more. 200 blocks, and the vendor was contractually obligated to ship for the price because his store was not set up quite right. Dude came here gloating about it. I mean, not only was it a crappy way to to business in my communist opinion, but what do you think the vendor sent him? "Hey Frankie, we need 200
specials for this clown in the USA."
I do the opposite. I gauge interest of a vendor, see what/if he is willing to sell me. I talk to him about what I want to make, see if maybe I can get an order that leans in the direction of say, longer blocks because I make a lot of Canadians, for example. Some guys that's no problem. You drop 1000 bucks in Mimmo's lap, he's real accomodating that way. I try to make it so these guys want to do business with me. I pay. Now. Here you go. Here's the money, thanks for the wood. There's no delay, there's no arguing about price.
The cutters know exactly what they are sending. Exactly. So the power is theirs. Period. Be nice to 'em! It's almost that simple.