So wich Zorin version should I pick and why. How to dual boot it with 2 HDD's (Win7 on the first one) and UEFI BIOS. I am a complete n00b at this so detailed step by step guide would be useful and much appriciated. Sorry for the bad grammar.
This may help,
I would suggest though using Linux/Zorin as your main OS and running Windows in a VM as outlined here:
A faster Windows with the security of Linux. Hope this helps.