You are new to trading. You are still learning. Clearly you are getting many new (albeit funny) ideas.
Keep it up. Keep learning. The fog will vanish and everything will be clear soon.
There is no need to look for “cheapest margin requiring option chain”
For buying you do not require “margin” - only cash.
For selling, margins are almost same across the market. Also the variation will be as per volatility in underlying, and also as per various factors in strike itself. Also the margin changes thrice a day.
And lastly, you don’t trade cheapest stocks or options you trade as per your setup.
You buy tickets of a movie you wanna watch and not buy the cheapest ticket of any movie.