Are you asking about a hypothetical build where money/cost doesn't matter or are you asking would someone be willing to put the time and money into realistically doing such a build?
If money and time spent is not an issue, I would do a diesel swap and SAS on a Land Cruiser 200 series, instead of a Tundra. IMHO, the LC seems to be the better starting platform for an overlanding build.
If I were actually required to spend my own money and time on such a project, I wouldn't waste a single $ or minute doing that. I don't know what reputation, if any, the Cummins V8 has in terms of reliability and longevity. The cost of doing both a diesel swap and a SAS on a relatively new Tundra would be huge (even through a professional shop). I'd think from a $ perspective, you're better off going with an imported Land Cruiser that already has a diesel and front solid axle or perhaps a Ram 2500 with the Cummins inline-6 or even a Jeep Wrangler diesel swap. I'm sure there are people and shops who are well capable of reworking a Tundra to the degree that you are asking, but for the time and money spent, it seems there are far more economical options out there....my 2 cents.