General consensus is that PG carries flavor better than VG, but doesn't produce clouds as easily. Keep in mind most flavorings are PG-based. I use a PG-based nic solution because it's easier to draw into syringes, but I barely add any plain PG to my DIY juices - I aim for 3.75 mg strength with 10/90 PG/VG ratio - after adding flavorings I end up with 80something% VG juice at 3.something% mg/ml strength.
For you, I'd suggest mixing a base liquid (using a calculator like eJuiceMeUp) at around 6.5 mg - after diluting with flavorings you should be in the 6 mg range - PG/VG ratios really depend on your delivery device and preference much as anything - if you're not sensitive to either medium, I'd go somewhere around 40/60-60/40 for a tank, and from 30/70 to 10/90 for a dripper.
As far as nicotine quality, I've had good luck with VapersTek and Nude Nicotine, bad luck with some unnamed others - if you're not sensitive to harsh flavoring that adds to throat hit you should be fine with any of the frequently-advertised nic base suppliers, I just feel like the taste of my juice should shine, and VT/Nude are the only bases I've found to date that allow that to happen...