Like I had said, I want to stick to a single coil. So would you still recommend the two RDA's you mentioned?
Yes you can do single coils on the Aeolus and duals on the Vector. Both are very leak free. My opinion .2 will be too hot for a new rda user, but no harm in experimenting with different resistance coils.
The problem with .2 on a single coil is the number of wraps to get to .2 Using 24g wire, you will only have 2 wraps. You would have to use 20g wire to get 5 wraps to come to .2ohms. Wrapping 20g is like trying to wrap re-bar.
Using dual coil 24g wire, you would have 5 wraps on each coil. 22g wire you would have 7 wraps to get to .2
Going to a .7ohm
single coil, you could use 24g with 8 wraps.
Also, another negative with a newb using a .2 resistance is the amp draw from a battery. You're looking at 21 amps, which is ok as long as you are using a good quality battery like a Samsung 25r that is rated at 20amp continous discharge, but a much higher pulse discharge. A newb might get pretty frustrated though, he will be sucking that battery dry quickly. If you are using some shit battery like a trustfire, he could potentially hurt himself.
A .5 build is drawing 8.4amps, and a .7 would draw about 6amps
Experiment with this
calculator before building. Hope all that helps