Some dual coil atomizers you can build a diagonal coil across the posts or some come with an airflow reducer/block off one side of the airflow, etc. I don't have that atomizer so I couldn't say with certainty.
I will say, that may be a tough build for your first build, I'm not the hugest fan of drop in decks they tend to be smaller, fiddley, and you are correct, building two coils will halve your resistance AND you will have more mass in your build. This often requires higher wattage to get a satisfactory vape.
I'd suggest trying to find a balance between the thickness of wire, and also check steam engine to see what coils and gauges of wire will minimize the amount of wraps needed to get the most satisfactory balance between resistance and needing to build a higher ohm's coil.
My (genuine) suggestion would be to buy a single coil DL RTA or RDA and start with that, unless you are SUPER dexterous and good at building and installing. I would have walked away from rebuildables altogether without that suggestion, honestly. I have a fine motor tremor though, so I'm kind of COIL challenged. Also, your dual coils (if that is the only thing you can build) really need to be equal in terms of build and installation, and that can sometimes be a challenge early on.
I would seriously consider starting with something else (personally) but some folks start out that way, with a deck from a drop in coil and do great with it, so it's also not an IMPOSSIBLE task, it just may be... harder. Although, "hard" can also be a great way to learn.
Best of luck whatever you decide.
Amna