@GStrade There are some disquieting reports on this site, still at the I-wonder-if stage, raising the question of whether Aorus TRX40 boards have an issue. You might want to study the situation and gather more info.
3970x-prime95-stability?
amd-threadripper-3970x-under-heavy-avx2-load-defective-by-design?
Airstripone makes a good point about the Define 7, which seems to be a nice refinement (at a cost) of the Define R6. I believe the “regular” Define 7 is the same size as the R6, and you would need the XL version for extra-large motherboards. However, the spec’d motherboard is ATX, and the R6 / 7 accept at least some E-ATX boards.
The S2 Meshify is quite similar to the R6 “open layout” setup, but only supports 3 HDs. “They say” that with high-quality fans (e.g. Noctua) it can be fairly quiet even with good airflow.
There are likely to be big changes in computing over the next few years; I dunno if 7-10 year life is viable. Airstripone’s idea about a more moderate initial build, with followup in a few years, is worth considering.
Have a Good Build!