I have recently purchased a Linhof Techno. I got some parts extra so if you need an adapter plate or magnifier just send me a message :-).
The 70mm image circle of Digaron-S will work on 54x41mm sensors but there will not be much shifting at all. The quality of the image circle is good to the edge, unlike on for example Schneider 35mm which may has 90mm image circle but only 75mm that is sharp.
Concerning the ground glass experience is much about expectations, eyes and technique. I have a Rodenstock 35mm, the low cost Apo-Sironar digital variant (not digaron-s), which is not at all as retrofocus as the digaron-S, which means that the ground glass is even darker and focus rail range even smaller. I still would say that it is usable on the Techno.
If you intend to focus precisely at flat surfaces at f/5.6 in tight and dark indoor situations, the Techno will kind of suck. There are tricks though like using a laser pointer to get a bright high contrast spot to focus at. Outdoor at f/11 it will be fine, although at this non-retrofocus wide 35mm you will not really see the whole scene at once, but you can look past the camera for that. I'd recommend a tilting loupe for the wide non-retrofocus lenses.
And if you like me use tilt very often, actually looking at the ground glass to see the effect of tilt is much more pleasing than using tables and estimations like you would do on a pancake camera (if not mounting ground glass on them too).
Unfortunately I have not been able to test the retrofocus rodenstock lenses, but all indications I have got is that every single one down to 23mm are easier to use - brighter and longer range on the focus rail than that non-retrofocus 35mm I have.
With the ground glass and wides, as light conditions get worse at some point one need to shoot partly in the blind. If you get experienced with the system you'll be able to nail those images too, and you can use tricks like strong flashlights, laser pointers or hyperfocal rail stops. If you unlike me use retrofocus lenses for the wides I would not worry much about it, I find it hard to believe that they would be as difficult to focus as some say. However, the ground glass image is small, the movements on the focusing rail must be precise, so if you have poor eyesight or are not so precise in hand movements it can be difficult. It is one of those things that some say is impossible and some say there is no problem whatsoever, so one cannot really know before trying out oneself. I took a chance and got my system without testing in advance, and I haven't regretted it.
While being a bit tricky (but possible) with the wides, for longer lenses (say 75mm and up) and decent light conditions working on the ground glass is a joy, better than a DSLR live view in many cases I would say especially when tilt/swing is involved.
I'd say that the Techno is great for one-shot scenes using movements, including tilt. If you instead of tilting etc want to use focus-stacking instead, then pancake camera is what you need since you want to set focus at different distances one after another without looking at a ground glass or live preview.
You seem to have a pretty large budget, and then I would go for the Rodenstock Digaron-W lenses, and digaron-S for the ultrawides. You cannot do much shifting with the digaron-S though when you have a 54x41mm sensor, and I think it is a little tight on the 48x36mm sensor too, but that is the way it is. The disadvantage except the price of retrofocus wides is that they are larger and heavier (can be an issue if backpacking) and quite sensitive - the copal shutters are not really designed for such heavy lens elements so the Digaron-W 32mm can quite easily get bent so you need to replace the shutter. If backpacking I would probably use a hard-case for those lenses.
If I were you I would consider the Kapture Group sliding back too. I have the Linhof original one, but their ground glass is not as good (=bright) as maxwell optics on Kapture Group back. Kapture Group also have better stitching options if you are interested in that. Bill maxwell can do a groundglass with adapter to the linhof original back but it is a bit pricey. There's also a rumor that Linhof is working on a new ground glass that will be brighter than the current. I am myself sitting tight for a while to see if Linhof comes up with something, if not I may eventually get a glass from Bill.