FWIW, a large scale very complex job will require a significant amount of money mated up with serious skills. Then add lots of time + frustration. Mix that all up and pour it into a fairly well equipped shop. If that sounds like you then sure it can be done. Lacking in any of those departments and the project won't get finished.
The outline you started with will need to be addressed specifically. The 240Z is essentially a unibody with front and rear subframes, which right off means extensive cutting. Got the coin I'd start by figuring out a tube chassis that could have a new aftermarket body adapted for 2 big reasons: 1) no rust to contend with and 2) not cutting up an original shell.
Custom REPLACEMENT COMPLETE CAB IN PRIMER LHD, 1969-1973, FOR NISSAN DATSUN 240Z Suppliers, OEM/ODM Factory - Jiangsu Juncheng Vehicle Industry Co., Ltd.
Everything you would do would be using aftermarket not OEM bits anyway.
My opinion...