How should I reconfigure partition layout to accomodate a dual boot (Kali2017/Windows10)

[KWinslow]

I have an HP Pavilion dv7 laptop.  I don't know if that's considered a notebook, but that board choice was better than the alternative choice of desktop.  If this post is more suited to be on another board, please feel free to move it.

Anyway, it's got Windows 10 installed on it.  It has a physical HDD that has an MBR-type partition scheme.  It already has the maximum allowed 4 primary partitions taken up.  I need to somehow knock down the number of primary partitions from 4 to 3, so that I can then install Kali on the 215GB of unallocated space (see partition layout below).

    I have a physical HDD with the partition layout of:

1) label=SYSTEM; filesystem=ntfs; size=199mb; used=35.48mb; unused=163.52mb; flags=boot.
2) label=OS (C:); filesystem=ntfs; size=350.37gb; used=139.52gb; unused=210.85gb; flags=-.
3) label=-; filesystem=unallocated; size=215gb; used=-; unused=-; flags=-.
4) label=RECOVERY; filesystem=ntfs; size=30.50gb; used=26.03gb; unused=4.48gb; flags=-.
5) label=HP_TOOLS; filesystem=fat32; size=103.34mb; used=19.14mb; unused=84.19mb; flags=lba.
6) label=-; filesystem=unallocated; size=1.00mb; used=-; unused=-; flags=-.

That partition "3)" of 215gb of unallocated space... I'm currently wanting to make it into a primary partition so that I can boot to a Kali Live USB drive and format it with an ext4 filesystem, and then install Kali on that partition. The problem I'm having is that it's a physical HDD that uses the MBR partitioning scheme and the max allowed number of 4 partitions is already taken by the partitions SYSTEM, OS (C:), RECOVERY, and HP_TOOLS.

I've already got 2 third party partitioning tools (MiniTool's Partition Wizard or Kali-Linux's Gparted) that'll take care of the partitioning, formatting, and filesystem setup. I'm just currently in the predicament of trying to find out what the best way to go about it is. I think so far that I have to either delete one of those primary partitions, make one of those primary partitions un-primary (ie- a logical drive?), or merge two of those primary partitions.

I'm just not sure what I should do, as it's been a looong time since I've had the rules of partitioning down pat (around the pre - WindowsXP era). If anyone (preferrably an HP customer support representative) should have any knowledge about how to change the partition layout around, please let me know as I've searched this scenario extensively over the last several days.  I usually keep searching a solution until one  tends to stand out as a consensus view, but so far about three options keep prevailing, but they are all about evenly favored (about %33 for each option) so I'm still not sure which approach I should take.

[KWinslow]

    Above (in the OP), where it displays an emoticon in two places, it should instead read as "the C drive". - KWinslow