For the K 4, you will want to buy a subohm kit then. Look at Tobeco, HCigar, EHPro or Infinite.
Subohm, single coil: Lemo, eXpromizer, Rose v2 clone, Flash e Vapor clone. You could also run the Aqua v2 single coil.
Turtle, the Tobeco and EHPro are both decent clones and you can get them for under $40. I own both and they preform great. The flavor is some of the best I've had from an RTA. I don't sub-ohm and 1 to 1.2Ω's is my sweet spot.
I have 5 total and the EHPro's is now my go to now, it just seems to have a better build quality but my Tobeco's are always built loaded and on a mod. The one from FT is ok but a bit of a PITA as the threading isn't as good on the base.
Good luck!
Wow, you really narrowed it down there. I've been looking at the Tobeco and EHPro. Apparently the Tobeco doesn't come with spare o rings, which is a problem for me. All reviews that I've read/ watched, no one has anything bad to say. Ultimately, what's the risk of buying a clone? Are the 4 clone co's that you listed solid or do they have many issues?
Yes, I have several items from all 4
You can buy rebuild kits cheap on fasttech that include o rings, post screws and insulators for the k4.
If you do your homework, there are several very good clones. I have quite a few I like as much as my authentics.
Thank you! Now I'm torn between Tobeco and EHPro.