There are several good MTL RDAs around:
- Berserker MTL RDA, 18mm (I use and like this for dripping: edit: authentic seems discontinued, but there are clones on FT)
- Etna MTL RDA, 18mm (I use and like this one for squonking)
- Galaxies MTL RDA, 22mm (I use and like this one for squonking)
- Cthulhu 1928 MTL RDA, 22mm (I use and like this one for dripping)
- Ammit MTL RDA, 22mm (I didn't get along with this one and gave it away, but many like it)
The 1928 might be a good option for you to try, it has 5 airflow positions on the cap (from a not too tight MTL to restricted DL), smooth airflow, a generous juice well, and is reasonably leak resistant. Here's a decent review:
I mostly use simple round wire coils in the 0.8 to 1.0 ohm range on mech/unregulated mods. There are other options though -- VandyVape has a few "superfine" fused clapton options (either premade coils, or wire spools) that can perform well at higher ohm MTL levels.
For nic, I use 10mg/ml 50:50, but, obviously, you'll have to find your own nic-level that provides the throat hit and nic satisfaction that works for you at MTL levels.