Based on your question, I am guessing you are running on limited time. Traditional PPC has you creating each listing and target key words. Google shopping (also referred to as PLA or Product Listing Ads) allows you to launch a little quicker as you are supplying data in a feed. You may want to start with this and then venture into traditional CPC.
We consult our clients on PLA/Google Shopping 90% of the time as the ROI on it, at least with our services is just over 30 days. You will see a lower CoS (Cost of Sale) many times as well for Google Shopping.