You are right, there are a lot of choices.
My first step up from an Ego Twist (which was variable voltage) was an MVP. It is both variable voltage/wattage. I have several of them and still use them today along with other devises. It is a small box mod (2600mah) with its battery self contained. A battery with a clearomizer (and charging cable) is around $40 shipped.
VP V2 Specifications:
Variable Voltage: voltage can be adjusted from 3.3 – 5.0 volts in .1 volt increments.
VariableWattage: Wattage can be adjusted from 6.0 – 11.0 W in .5 watts increments.
Ohmsmeter : Reads resistance of your atomizer/cartomizer/clearomizer.
Puff Counter:
Short Circuit/Atomizer Protection:
Over-Discharge Protection:
Battery Level Indicator:
Large battery capacity: iTaste MVP e-cigarette built-in 2600 mAh polymer Li-Ion rechargeable battery.
High compatibility 510 connector: Thread fit iClear10,iClear16 ,iClear30 etc
ON/OFF battery switch:
10 seconds cutoff:
Passthrough:
Remembers last set voltage or wattage :Remembers last set voltage or wattage when the battery is turned off and then back on.
Built-in 3 digit display : Digital display shows Ohms meter, Voltage /Wattage setting, number of puffs taken since last time the battery was turned off.
Portable power source for electronic products