Replace 1 TB Internal 3.5 Hard Drive with Dual SSD

I am wanting to replace the 1 TB spinning hard drive with two SSDs. I understand and have researched on adding a SSD and keeping the spinning drive but I am wanting to replace it with 2 SSD. A typical 3.5 hard drive should be more than the thick enough to cover the thickness of two Samsung 840 EVO drives that I am considering. Does a kit already exist that allows for this? I know Samsung makes a desktop kit that allows 1 SSD to be mounted in a 3.5 inch bay but that is only 1 SSD.

Also I have read some on special firmware on the Apple drive for temperature sensing, is that still accurate? Would I just be better off leaving the OEM drive intact?