I can recommend you some easy for build and wick RTA's.
1st Kayfun v3 mini
2th Byka 6
3th Doggystyle RTA
They are flavorful, no leaking /except of your mistake with cotton, wicking way or bad o-ring's/ and easy to use atty ...only Doggy is with bottom filling. I'm use those 3 for everyday vape...