Every supplier that reaches out to you will say they have a winning product with the wow factor but in reality their only intention is to sell their product.
I suggest to do extensive research on product hunting using different product hunting tools like Ecommerce hunt and many more that are specially designed to find winning drop shipping products.
Here are two methods to identify winning products:
1. In your Facebook go to ads and check out all the drop shipping product ads and see the social proof if the engagement is more then you can follow that page to find other products they have.
2. Use Ecommerce hunt tool Ali express drop shipping products.
Its good to hear that you are ready to run two stores, we are ready to help you in succeeding your stores by providing winning products to your store from our suppliers through app directly with single click. You can have your own branding and customized labels on products by using "Appfreaker Supply".
Every supplier would say his product is a winning product and you are the only one can decide based on your sales channel, the target customers and the competitors. When you are successful in your test sales, you is still risk your supplier may let you down. Whenever you place order with large quantity, you may need to check about the supplier's background. You can try to hire a third party quality inspection company to conduct a factory audit. There are a few good companies that you can review such as SGS, Intertek, HKQCC etc.