Need some advice on popup methods

Hi guys,

I am starting out with popunder - content locking method and I need some technical advice.
What would you recommend doing in my place: to buy new domain and hosting every time I change the offer? Or to buy a general one with one hosting but just swap landing pages? Is .com domain necessary for this type of website?

Also, do you recommend buying landing pages or software to make them, or create them from scratch / download from here?

Thanks