Uhm, I am confused. The 3.5" HDD surely will not fit that's why I thought of using male to female sata cables to be able to connect the 3.5" HDD from outside the laptop. I also think that this is the easiest (and cheapest?) way to do this (using the 3.5" HDD as the main HDD of the laptop).
I did not quite get what Lighthouse and whs is trying to point out. So, connecting the 3.5" HDD's power to the laptop's using a SATA power cable (male to female) is not safe?
And to make it simple, If I were to use this:
to connect the 3.5"HDD directly to the laptop, wouldn't there be any issues with the power?