Query : Are you installing Linux onto a PC or this a laptop?
2nd Query : Do you have a spare HDD?
Reason I asked is this, and speaking from experience, is that if you are fine with an install that will permanently change the way your drive boots, (you can't just remove linux if you don't like it or if something goes wrong, however unlikely, and your linux boot is screwed up) go with option 1. That is install linux directly onto your windows HDD.
Option 2 is what I am doing right now and it actually saved me from ALOT of heart ache / time wasted.
I have several spare HDDs so I disconnected all my other HDDs, and did a full blown install onto this spare HDD. As I am (still) experimenting with the different distros (From Ubuntu and all the other *buntus, to Fedora, to Slackware, to OpenSUSE to Mint ....) installing them fully (yeah I know I can live boot them but I prefer to see them in action in "real world" usage and that means having these distros installed onto an actual HDD) then nuking the one I am on and installing some other distro.
And trust me, I have had my MBR screwed up by ubuntu's Grub just recently. How bad was it? No matter what flavor of Linux I installed, ubuntu's grub just pops up, then freezes. Even with Gparted trying to nuke the MBR didn't work. In the end I had to do a full wipe that took a several hours to fully wipe the drive before it would allow me to install anything at all.
Besides. Now I have this drive plugged in along with my Windows HDD and I can UEFI boot into either one at any time and I can remove and nuke one or the other HDD without damaging the other.
I do have a third drive as my "common" repository drive though where all my downloads / data / docs / stuff goes into that can be read by both system. (or you can always install a NAS for that.