You can use a drip tip on a cartomizer. Your supposed to take the white cap off and then put the drip tip on. What cartos did you try?
If thats the only reason your giving up cartomizers than personally I think thats...

.
If your going to go back to using an atty and cartridges, I think you will be very dissapointed.
Different ohms arnt what produce more or less vapor. Higher ohm produces a cooler
vape, while lower ohm produces a warmer
vape and more TH. Most people prefer low resistances(lower ohms).
For an eGo I would get between a 2.0ohm-3.0ohm. Using below 2.0ohm, like a 1.5ohm or 1.7ohm you can potentially fry your eGo mosfet, which kills your PV. Some eGo users use below 2.0ohm and dont have a problem, but many others have also fried an eGo using below 2.0ohm. So thats up to you if you want to take that risk or not.