Depends. More details are needed. Here are some questions off the top of my head.What is your goal?
What size enclosure can you fit?
Price range?
Are there any models you are currently considering or maybe some you will absolutely not use? Which amp(s) are you using?
I just like the idea of blowing someone's mind that I have only 1 12 and its just some thoughts I had.I forgot to ask about the title of this post. Why are the options 1 12 on 2000w or 2 10's on 1200? Do you have 2 different amps to choose from?