Hello, Johnson and a belated welcome.
I had a heart attack almost 20 years ago. After the surgery to put in 3 stents, I mentioned to the doc that it was so easy I remembered falling asleep during the surgery. He let me know I didn't fall asleep, but went into cardiac arrest! That really changes one's outlook on life. As an interesting (I think so anyway) note, I asked him on a follow-up visit which was going to kill me first, smoking or extreme work pressure? His response was something like "your asking me to condone smoking". He also said he was trying to buy me 15 or so more years and that had I been into him for testing before the heart attack, they would have never seen any indication that there was anything wrong.
So I tried to quite smoking (many times with different methods) and follow all "the rules" to a t, but it was all too overwhelming. I did as many as I could handle while some, like having my morning regular coffee (3 cups max) became an acceptable risk for me. As for smoking, I continued smoking and my family and doc all pretty much accepted that I would never quit and suffer the consequences. He is very happy that I have quit the cigs with vaping, but did suggest I work at cutting down the nic level. My annual visit in a couple weeks will be more interesting and I am anxious to get his response to still vaping and cutting back to 6 nic.
Well, I passed that 15 year window a few years ago, still smoking away, and then found vaping. I started with 18 nic and stopped smoking day 3 and have never looked back. My simple advice? First, stop looking at the checkbook! Finding what works best for you right now is priority number one. Find the equipment that gives you "the feel" and experience you desire when vaping. Instead of buying two of something you want to try, get a couple setups with differences you are interested in trying. The one you like the least makes an OK backup until you are ready to move up. And don't be surprised if you start looking for something even better after a while.
Find yourself a good juice at a nic level that works for you. Then find another, or two, or three so you can change up as you like. Don't be too concerned with nic level or pg/vg ration until you have what you enjoy and keeps you off the cigs. Once you've found the equipment and juice that keeps you off the cigs, then start playing with the finer details. Start with getting off the cigs then progress to searching for that perfect vape as the cost permits.
That is just my 2 cents worth and hope there might be something of use to you in your endeavors. Good luck with your health and vaping experiences.