I am looking to buy cartomizers for my Cartomizer tank unit. Below is a picture of what I am using.

I am looking at smoktek, but there are so many cartos to choose from.
What is the ohm difference? 1.5, 2.0, 3.0 ohms.....I believe I am using a standard 3.7 amp battery. Does the ohm amount mean anything??
Single coil vs. dual coil?? Does it matter?
I am just looking for an inexpensive cartomizer that will provide good vapor. Till now I have been using our local brick-and-mortar vendor who sells 1 cartomizer (as seen in my image) for $10. There has to be a cheaper online alternative as they only last about 1 week.
Thanks for any help you can provide and I will do my best to answer any questions I may need to provide to get a good decision.
Chris

I am looking at smoktek, but there are so many cartos to choose from.
What is the ohm difference? 1.5, 2.0, 3.0 ohms.....I believe I am using a standard 3.7 amp battery. Does the ohm amount mean anything??
Single coil vs. dual coil?? Does it matter?
I am just looking for an inexpensive cartomizer that will provide good vapor. Till now I have been using our local brick-and-mortar vendor who sells 1 cartomizer (as seen in my image) for $10. There has to be a cheaper online alternative as they only last about 1 week.
Thanks for any help you can provide and I will do my best to answer any questions I may need to provide to get a good decision.
Chris