I like RTAs I am not the most proficient builder of all time, but I have several RTAs I get along well enough with to KNOW I can bring them out with me and thye surf in my purse and don't leak at all. If building is time consuming, I suggest rayon as a wick. I LOVE rayon. It lasts longer than cotton and withstands more heat without burning. It's also way easier for me to use. Rayon stopped most leaking cold turkey. It's great stuff.
As far as the Nautilus coils, I have a few drop in tanks I am not willng to give up. One is the Zenith (which can be QUITE airy) and the other are my two Kabukis that take N2 coils.
So, I stocked up for life. The thing is, I have so many things in rotation, it was easy enough. I bought 3 "cloned" N2 coils from Fasttech to test out. I have lots of real coils ,but I finished up with those.
It is extremely easy to rewick the Joytech CLR coils and they might be right in your wheelhouse.
But if you are in this for the long haul, finding a few rebuildables you like, that are tanks, not drippers, and stocking up on coils cheaply during sales and/or from Chinese sites are the way to go, honestly. I don't actually TRY any new tanks anymore, I know what I like, and I have plenty of coils (the Zenith is also one.)
Good luck,
Anna
ETA: I might suggest the doggy style (really only available as a clone, from fasttech.) I don't know which is the airiest but it is an easy build, a fantastic tank, and it can get qutie airy. The Siren V2 is loved or hated (I love it) and you can mostly only find the 24 mm version, but some places have the smaller one on sale. Very airy MTL, very easy build.