Now that I think about it, I suppose I need not even worry about the newer UEFI as Linux will be on a completely seperate drive, and windows on my other. For example, I am currently running Linux on an exteranl drive now, with Win7 Pro on my internal C: drive on a laptop, I changed the Bios around to boot from the external first. So, I just turn on the exteranl (on/off switch on the case) and it boots into Linux. If I want Windows, I turn off the external, and it boots to windows.
But how you boot install media for both Windows & Ubuntu is how it will install. So if you want BIOS be sure to turn on BIOS/CSM/Legacy in UEFI/BIOS and boot installer in BIOS mode.
When I installe Linux (over and over again due to NVidia issues which is another story), I completely remove the internal drive so there is no way it could get mess with the windows O/S; plus, I purposely do not run grub update after the install and reinstall of the original interanal drive. I think this way, the two O/S are completely away from themselves.
So, If I have two drives on the new project desktop computer, when I install Linux, I'll simply unhook my Windows drive, and load Linux on the second drive. So again, I dont think whch BIOS would matter, since grub and MBR never mix...