you'll probably want to go with a variable wattage mod-- rather than a mechanical mod. Two great choices for someone just starting out with APV's would be the Innokin iTaste MVP or the Vamo v5. The MVP has a built in (non removable) rechargeable battery while the Vamo has removable batteries. you can use the Vamo with 18350 or 18650 batteries.
the Vamo is a tube mod, while the MVP is box shaped.