Any old atty will do, but really excellent dripping comes at a cost. My favorite is the Cisco 306 attys (Avid Vapors always has a sale going on for 2x attys + 1 Delrin 306 drip tip). They last a long time and taste great. You may also want to pick up a bottle of 100% VG (CVS Pharmacy "Pure Glycerin USP" $5/6oz) to use as a taste changer. In between flavors simply drip a few drops of pure and puff through it an then add your next flavor. I'm not familiar with the Tornado, but for 3.4v I'd go 1.5ohm and for 3.7v+ I'd go 1.8ohm. Also, for anything "LR" be sure your batt is at least 650mAh or bigger (below this LR can damage your batts or shorten their life considerably).
Good luck, enjoy.