The blog identifies pretty much all of the mainstream sources that I'm aware of.
Skytrex has been out of the 1/300 scale 20th century armies business for some time. They sold their molds off, mostly to Heroics & Ros, some years ago. Many of the old Skytrex models could be found in the H&R catalog, or at least were up until the pandemic times…
I would also suggest watching 3D print vendors. Shapeways is a top marketplace for 3D print vendors:
link
Among the vendors on Shapeways I have so far only bought from Masters of Military, but I was quite delighted with what I purchased. MofM has some of the best prices of the vendors on Shapeways, but they are still pricey compared to soft-metal casts. However, you can find a fantastic variety of odd-ball kit that really gives character to a wargaming force, and in my experiences so far the quality has been superb.
A Polish force is probably going to be infantry-heavy. There just isn't much of tank fighting to re-fight on the tabletop. Among the vendors with Polish infantry at this point, GHQ will give you far-and-away the best looking figures. Up to you if that makes a difference.
The shortcoming of GHQ, even after you get over the price difference, is the variety of poses and equipment. It's hard to make a one-to-one unit scale infantry force, as you just don't get enough of some pieces (like riflemen!), you get too many of others (like officers), and there will be some infantry weapons at the company- and battalion-levels TOE that they just don't provide.
H&R's older figures are somewhat less detailed, but still clearly usable (in my book). The figures are tougher -- they stand up to wargame table usage well. They poses and composition of the kits are the best of the vendors I know. H&R's newer infantry are very much better in details, rivaling GHQ. They retain the toughness, and the great selection of poses and weapons/equipment.
However not everyone makes Polish infantry.
So you may want to consider alternate figures that you can mix in to your force as you seek to build it out.
In my experience, at this scale the key visual differences are going to be headgear, LMG magazines, and backpacks vs. shoulder rolls.
The Poles in 1939 had a rather distinctive and unique helmet, but at this scale it is well enough represented by either a Russian or an Italian helmet in my view. A lot of Russian infantry figures are modelled with shoulder-rolls (half-shelter / capes or overcoats with personal belongs rolled in the middle, slung shoulder-to-opposite waste). I do not see this used by Polish soldiers, and so if you are choosing among Russian soldiers you might look for figures with backpacks. The Poles had recently transitioned from French Adrian style helmets, which were still in use (though not widely). So a few French figures can probably be mixed in too. But the French manteau (greatcoat) was pretty distinctive, and not present among Poles, so care should be used in selecting the figures.
The Polish LMG was a derivative of the BAR. It had a magazine beneath, which makes it distinctive from many other squad level automatics of the time. I have found that working the magazine issue is often enough of a kit-bash to fit other army figures into a 6mm force, and I assure you slicing /clipping a magazine off is much easier than shaping and adding one. French (top mag) or Italian (side-mag) figures might do quite well.
All just ideas. Always interesting to start a new force and figure out how to build it up into something that you can use and take pride in.
Please keep the thread going if you do proceed, and let us know / see how you are progressing.
-Mark
(aka: Mk 1)
