Selecting the right company to work with means you need to explore candidates and match them against your requirement list.
Not only the right company needs to have the required matching product or technology but also the required Supply & Support/Services Flow. It is also important to agree upon the Business Value Chain.
Selecting the right partner is not a quick job. It is a number of areas that needs to be analyzed and determined to be a match. The first area is the product itself but this is not the only one even in reality and my experience this is where the first attempt ends. Add some experiences and other functional views and more areas show up.
Connecting with a Start-up is maybe not the ideal partner since their size, capabilities and focus most likely do not match your criteria for a sustainable multi-country operation.
Supply and Support Flows
Depending on the Business Model you want to go for this is a very critical area for selecting the right partner. Unless you are integrating a component into your product and you will drive the Supply and Support Flows, these Flows must match your criteria.
If you are the Prime towards the customer you need to secure that you comply to all Trade Requirements. This means you need to secure that your Partner can support you with all the information you require. If your intended Partner do not yet have an export business it will take an effort for them to comply.
An important check to perform is the sustainability of the company you consider for a cooperation. Financials and ownership but also Corporate Social Responsibility to match your own profile are key to check. Your proposed cooperation most likely will have life cycle of at least five years so it is important to pick a company that will support you all the time.