Throat hit is a product of PG, as well as some flavorings and high % Nicotine, too. PG is the primary though.
If your mixes are 50/50 PG/VG or higher VG content, get your Nicotine mixed in VG. If you like thinner juices with more throat-hit... higher PG mixes, then get your Nicotine in PG or 50/50 mix.
If you're mixing a juice that is 20% flavoring, and you use Nicotine mixed in pure PG, then you'll NEVER get your mixture higher than 30/70 PG/VG mix with 10mg Nicotine strength... it just won't be possible because the flavorings and Nicotine are PG based. If you go higher than 10mg Nicotine strength (using a 100mg/ml PG base), you'll lessen the VG % because you'll use more PG-based Nicotine. The MAX VG % you'll get (using zero Nicotine) is 80%.
NOW... here's a kicker... All of the above is assuming you're using 100mg/ml (10%) Nicotine base. If you're using a weaker base, then you'll require more of the Nicotine base to reach your desired level of Nicotine strength. For example, 20% flavoring, and using a 6% Nicotine base (60mg/ml) in PG... your max VG % would be 63%. Make sense? Using a 36mg/ml stength Nicotine base... your max VG % would be 52.5% (with the final juice being only 10mg strength).
If you're happy with 50/50 mixes, or even 40/60 mixes (max 20mg/ml Nicotine strength, using 10% Nicotine base), then you can use PG-based Nicotine, otherwise, obtain VG based Nicotine.
Another thing to consider is the shelf-life... PG has a shelf-life of something like 10 years (although DOW chemicals says only 2 years, but they are in the business of SELLING IT)... VG has a shelf-life of about 5 years. Nicotine has a shelf-life of 2-years... all of these are non-refrigerated, dark containers. If you freeze or at least refrigerate your PG/VG/Nicotine, they will last MUCH longer.
10% Nicotine in PG base will have a shelf-life of between 6 and 8 years. The same in VG will last 3-4 years (again, non-refrigerated).
So, if you want to buy Nicotine in bulk... PG will last longer than VG base, but if you freeze them in air-tight dark-colored containers, which are full to the rim (zero air in the bottle)... they will both last pretty much forever.