Installing Sierra on partition

How's it going guys? Last night I decided to try to install Mac OS X Sierra onto one of my three hard drives. Hopefully you can excuse my ignorance as I am a bit new.

I'm running a Intel core i7 4790K with 16GB of RAM and a GTX 1050ti on a Gigabyte Z97N-wifi motherboard. I have a 120GB SSD, this drive contains my windows 10 install. The second and third drives are simply storage. The second drive contains programs and the third contains media and what not. The second drive is a 1 TB 7200 RPM and the third is 2 TB 7200 RPM.

My BIOS is Dual bios and unfortunately windows was installed as MBR and thus only boots in legacy bios. My other drives however are all GPT. when I set the BIOS to boot from UEFI none of the drives show up. However, when its set to legacy they are all shown (I'm not sure if this matters considering that I can load Clover and the installer from a UEFI USB).

I do not own a Mac, however, I was able to set up a VM and use Rampagedev's guide to attempt to set up a bootable USB and install Mac OS on a 250 GB partition on my second HDD.

Initially, I wasn't able to boot Clover at all but this was fixed by using OsxAptioFix2Drv instead of OsxAptioFixDrv. Once I used Fix2 I was able to boot Clover and get into the installer.

Then I reached another snag. I was unable to partition/reformat my partition made in windows to Mac OS X Extended (Journaled) when using the disk utility included in the installer. I was getting a "mediakit not enough space" error. I fixed this by using GParted from a USB stick and making that partition into HFS+. Once I did that I was able to enable journaling and I was also able to repartition it using the disk utility.

Unfortunately, I'm stuck again. This time I am unable to choose this partition to install Sierra on as I get a "This disk cannot be used to start up your computer" pop up when I select the partition in the installer. Because I already had Data on this hard drive I thought that maybe OS X needed to be the first partition on the drive. I used Gparted to switch the partitions so that the OS X partition was first and my windows data was second. This however did not solve the problem.

This is where I'm at now. I'm not sure what to do here and I would really appreciate any help. Thank you.

Edit: I'm hoping to find a way to fix this without completely wiping my drive as they already have stuff on them.