First build, dual 2 ohm vs 4?

I’m going to be doing my first legit build, right now I have a cheap 10 inch sub in my ford ranger extended cab, but, I’m going to get 2 sundown SA-Classics 12” with an enclosure made for them. I will be buying an amp to go with it, and I understand it a bit but I’m still a nube to it, so when buying my subs, should I get the dual 2 or 4 ohm?? That sort of thing confuses me, I’d like to do things as properly as I can so any tips are appreciated, thank you.