Hello to all

I am French and my English is not really good. I am an owner of K750i which I would like to update. I would like to install the R1CA021 or R1BC002 version (I have at present the R1L002 version).
I saw that we could use Setools2lite but I do not know which firmware to download among all the proposed versions:
CID36 or CID49?
RED or BROWN?
EUROPE1, 2 3 4 or 5?

I also have the second K70i the firmware of which is the R1CA021 version, is it possible to read it to transfer it towards my other phone (that with the version R1L002)?

Thank you for your answers.