Phone [Q] Moto G Single & Dual SIM Firmware

Hey guys, i'm just curious,
Is the dual sim version & single sim firmware different?
I mean if there is a custom rom for the single sim version,
would it work on dual sim version?
I'm confused, because in my country it looks like there will be only the dual sim version,
I want to buy Moto G so bad, but if i can't install the single sim version custom rom on the dual sim version,
it would be useless (because i like to install custom rom on my phone) and I won't buy it,
So any ideas?
Thanks
Fcked Up!