You have bottlenecks:
writing to tape
restoring from tape

You may need to plan a production shutdown starting Friday at noon, and expect the new system up by 9 am Monday - if you have Sunday delivery. You have to migrate applications. You have to migrate users. You have to update TNSnames settings and file protections on the new boxes. You will have to update software on PC's to use the correct forms servers, etc.
Don't forget ftp/sftp/ssh processes and their keys, etc.

We just did this. We did a trial run, had problems, corrected them, did another trial run had a few problems, then did a real push. For each trial run we had to get users out of production Friday early on.

It is NOT just the Oracle dbf files you have to worry about.