Yes, all the RTAs I mentioned are MTL. If you want something more DL I am not your gal for suggestions. I will say a RTA dedicated to MTL well the vape can be CHANGED a bit, in the sense that sure, you can put a lower resistance coil in there, maybe drill out some airholes and a different drip tip on there (possibly) but by the time you do that, well, you might as well get a dedicated sub0hm RTA if that is your TRUE desire. I mean... no point reinventing the wheel when there are perfectly good RTAs that are designed for sub0hm.
Yes, you can buy supplies now if you wish, and they can sit there until you are ready for them. I am not entirely certain if that's the wisest use of your funds since I'm thinking that probably importing such items is not going to be as much a red flag as say, and atomizer. But, I don't know that for certain, so....
The Joytech clr coils are the ones I was talking about, personally. I think (but oh, don't quote me) that they also make a 0.5 coil which may or may not be a temperature coil material, I'm not 100% sure.
My favorite tank for that coil is the Totally Wicked Oddessy tank, you can get one from buybest for like 36 dollars and no shipping (it's a China based site) which is totally reasonable for that tank, I've seen it ON SALE for like 54 bucks other places. The tron S and the Joytech Ego One Mega are also both PERFECTLY reasonable tanks I think and you can get them for a lot less. I will note that me, the joytech tanks, and that coil have had a very hard time getting along, I've had troubles getting them to read, although in retrospect, the ones I still have left had a much easier time making and staying connected than some of my initial tank choices in other words, it may have been the mods I chose and I will ALSO say that I still prefer the Oddessy tank it's just BETTER but also the joytech tanks are probably fine and I should also note, no one else on that thread has had ANYTHING near the difficulty *I* have had, and there are certain manufacturers who I don't get along with well and joytech is one such manufacturer, EXCEPT for that coil which I happen to LOVE. In my oddessy tank.
LOL good luck!
Anna