Hi BWG,
Welcome to the forum!
Another thing to keep in mind when going for the TH.
In most cases, the more PG an e-juice has, the stronger the TH. Also, most folks think that menthol, cinnamon, peppermint, and a few other flavored juices produce good TH.
VG is usually known for it's properties as a vapor producer with less of a TH.
Some folks like 80%PG/20%VG. Some 70/30, some 60/40, and still others 50/50.
Also, there are those who like all PG e-juices or all VG. Everybody is different.
You'll need to experiment for awhile and find what blend works best for you.
You've received advice from members as to what they consider to be a good e-cig to own.
IMHO, any of the above mentioned PV's(KR808, 510, Screwdriver, eGo, Riva, or a 5volt device), should provide adequate TH for most vapers.
Good luck in all of your future vaping endeavors!