I think the Sako Rk95 gas block would be scarce as hens teeth, hense, a no go.
I think the Galil sniper would be a very popular option for the .308 Galil build. True, people don't often do heavy barrel - Sniper builds, mostly because the gas block for the heavy barrel is non-existant, not because there's no interest. The gas block is really the only part you can't do without, and is a difficult part to do, even for a very good machinist. The muzzle break, handguard, even a reasonable rendition of the buttstock can be done. The receiver mounted bipod might be "a little" tricky, but again, a reasonable rendition can be done.
The need for having all the rest of the Galil sniper parts is not an issue at all for me. I'd just like to have the general look, feel, and, with a good Douglas SS barrel, increased accuracy. A sniper "weight" heavy barrel (which can easily made), GAS BLOCK, wood - folding hopefully - buttstock, and bipod mounted in the same location as the original Sniper, not necessarily identical to the original, but hopefully folding up into the handguard.
I also think the AR way outsold the ARM, at more than 10 to 1, and still far outsells them in the new builds, as shown in the Golani AR vs. ARM production.
The SAR is not a very big seller, though it's super cool, it needs the Feds O.K., and a lot of us don't want to deal with that. A pistol version of the SAR would be legal, but, the manageability, and coolness drops dramatically, for sure! And sure, you could do the SAR gas block, with a little cutting. Of course you'd have to drill the second pin hole, and it wouldn't have that shoulder in the pin area. I'd rather do a straight cut to "make" an SAR gas block, that Dremel off the whole ARM bipod mount area, and make it look factory, that'd be a lot harder.
The chrome is also, in my opinion, not a deal breaker. They could be nitrided, which is far, far better for rust inhibition.
I'm quite sure CNC Warrior could make an absolutely perfect Galil gas block, and this is probably the only shot at getting perfect, new, Galil gas blocks, ever.
Lastly, I don't think there are lots of SAR, or any other Galil gas blocks around at all, certainly not very high quality ones that can be purchased in multiples.
I'm thinking, for pure sales numbers, (and my own selfish desires)
#1 IMI AR gas block - 5-7 pieces (ARM would be "acceptable", (but not preferable to the AR), as a good machinist could easily profile it to make it look like an AR)
#2 IMI Sniper gas block - 3-5 pieces