Updated HP Windows 7 x64 to 10 & Want to Install Ubuntu 16.04.1 Dual Boot

HP laptop, updated from Windows 7 x64 to Windows 10 (standard BIOS) with two 500 GB hard drives & 8 GB RAM wanting to dual boot Ubuntu 16.04.1 but running into issues with the disk 0 / sda already having four partitions and quickly running out of knowledge!

I had previously deleted the HP Recovery partition on Disk 0 and shrunk C: volume so I had approximately 100 GB unallocated space for Ubuntu install but during Ubuntu install realized I still had the 3 partitions and so wasn't sure how to work around that with either drive.

So I extended the C: volume and removed the 100 GB unallocated space until I could figure out what and how to setup.

Here is where I'm at in Ubuntu install when have the option to install alongside Windows 10 or Something Else:

Install alongside Windows 10 looks like it will install on sdb / second hard (D drive which seems like it would be easy and I would be fine with that, only not sure if I will have any boot issues, or if this is even ideal, etc? Would it really be that simple?

When I select Something Else, these are the options I'm presented with, keeping in mind I removed the unallocated space I had previously made but removed due to already having 3 partitions on sda / disk 0 / C:

With this configuration, what is the best method to install and dual boot Ubuntu? sda & sdb, sdb only, should I setup partitions beforehand?

Assistance is greatly appreciated, thanks!