Remember whatever device you get, if it doesn't have a built in battery, you will need to buy good quality batteries and a battery charger. This will likely add around $30-40 to your purchase price. Also, if you buy something like a Kanger Sub Tank or a Atlantis (or most other clearomizer type toppers) you will need to purchase the coil heads (as you said you've never rebuilt before) These heads are around $15 for a pack of 5.
Personally I don't like recommending any devices without a lot more information. A $15 ego twist with a $20 nautilus mini can work just as good as a $300 Vapor flask with a $200 Kayfun V4 on it depending on what you expect from your vaping experience.
What are you looking for? What have you used before and what did you think of it? Are you vaping to stop smoking or for something else? What type of liquids do you prefer (high VG or not?) and how much tinkering with your equipment are you comfortable with.
Do you prefer wood, metal, tube or box? Is battery life important to you? I could ask another 100 questions here about your preferences. There are just so many options out there.
Finally, I would recommend having a look around the
Variable Voltage APV Discussion section of the forum. It might give you some ideas as to what is out there and some of the pros and cons about those devices.