Some trusted hardware sites:
LiteCigUSA.net
Liberty-Flights.com
Cignot.com
Vapor4Life.com (their Vapor King is KR808D-1 but in fancier colors)
MyPVShop.com (not the best price but you can choose the color of each kit part)
If you buy a 510 or Ego buy a Joye-branded one because there are some substandard clone parts around.
Research what the actual popular models are - watch the Newbie videos in the sticky threads here, and follow the thread with Library in its title to a multipart guide. Ignore the super-minis in the guide unless you a an ultralights smoker willing to screw with tiny carts because super-minis usually don't satisfy anyone for more than a few weeks.
Juices sites - so many trustworthy and popular ones
FreedomSmokeUSA
Backwoods Brew
Velvet Vapors
Madvapes
and so many more
Most popular starting models are these minis and their fat-battery more powerful versions
Joye 510 (most common)
DSE901 (a softer hit but tasty)
KR808D-1 (2-piece cartomizer model, aka Vapor King at Vapor4Life)
The fat battery versions include Ego or Riva 510 (510 based), Riva 901 (901 based), Elegant Easy from CigEasy and I think a model from Bloog (KR808D-1 based)
You will notice none of these are the glitzy "name brands" you'll find on the web or at the mall with "testimonials" and "reviews" because many of those are rip-offs. If you buy at one of those sites then do not buy any free trials, don't buy anything anywhere that doesn't sell blank carts or cartomizers, don't buy anywhere that charges more than $18 for a battery or doesn't sell parts at all, don't buy anywhere that claims a cart last as long as a pack of cigs, etc. You may still end up with a good or crappy PV but at least you won't be excessively ripped off.