@Bernd **********
honestly IF I knew I had the 800K already in the bank ready to go, I'd just come back visa exempt and high tail it roght over to the immigration office and apply for the in country Non-O visa for 2000baht
I wouldn't even screw around with getting the 90 day Non-O at a thai consulate or even a tourist visa I'd just bounce out and back in to wipe the slate clean, get on a 30 day stamp and go from there.
I mean worst case he comes in visa exempt, can't get it together fast enough and has to take the one 30 day extension you're allowed for 1900baht to by more time, that's 2 months and should be more than enough time