Hi Francis,
Your location and hemisphere has some outstanding Bladesmith, that are more than skilled enough to make timber framing tools, and some have in the past (retire or gone now that I have know.) I would reach out to some of them first to see what is possible? There seems to be a very healthy, thriving and growing interest in traditional building methods including timber framing in Australia, so there is certainly a market for these tools.
Your current list is very comprehensive, and seems like you have researched some of the common options thoroughly. I can no longer recommend Barr Tools to students or DIYers. The results over the last decade have been spotty, at best, with many of their tools getting returned from those I know. To Barr’s defense, they have always stood behind their tools (thus far?) but the quality is just not what it once was (I own some near original tools.) Nor are they comparative in price, from my perspective and experience, when up against some of the young tools Smiths out there making very affordable alternatives…that are equal to or better in quality and workmanship...
Of your list, I have only heard great things about Sergey’s work, and his prices are near the lowest out there for the great quality he produces. He is also open to custom work as well from what I know, but there will be a wait for that...
I would recommend Janis’s (aka: Autine) work over the “Northmen Guild '' just because he is one of the first doing it there and has been now for almost 20 years. Jacob (aka “Northmen” or “John Neeman Tools” a made up “marketing name!”) has done well with his company and compatruats for sure, and makes fine tools. However it is all a bit too “glitz and glamour” for my personal taste ($$$)...with way too much marketing. I tend to be faithful to those that communicate directly with me as Janis has always done about his tools and what a Timberwright may want. I still recommend him when this topic comes up for ordering from that region...
As for, “...What to get?...”
That all depends on your style of timber framing, and experience for the most part. I use (and have used) a lot of very brittle Japanese timber framing tools over the years and I love how they work...when well made. I hit them a 3 pound steel stone carvers mallet whether working hard or softwood. Breaking them is a matter of skill set, refined technique, and understanding the wood being joined...not necessarily the Janka rating of a wood...at least in my experience. Pick your style and refine it...don't worry too much about wood hardness...
So, for me, I would start with gouges, as that is my got to chisel for most of my day to day work, whether its a out cannal spoon or pattern makers gouge and I never go without a 90% V gouge (aka corner chisel) being within reach. From there it would be a 30 mm to 90 mm slick or long neck paring chisel...and good selection of planes. Many of these are going to most likely be Japanese or custom made tools. All of these that are striking tools will be hit most often with a 3lb (or larger) stone carver's mallet, usually a bell style from Trow and Holden. Yet again, that is just my style...
As for sharpening...that too is style and personal. For me if I can’t get a shaving hone in less than 90 seconds from a dull (not damaged) chisel or edged tool I would change the system if using a powered sharpening method. By hand, it all depends on what works efficiently for you? I like diamond and water stones with honing methods down to 0.01 micron.
Hope that helps...
