In most cases, order a professional name and trade mark availability search for the proposed start-up brand. If the ambition is international then the availability search should be internationally. Getting an available domain is hard enough. Use experienced search professionals to implement a name strategy and seek to adopt a brand which can be a registered trade mark, in target countries, and for a broad range of products or services. It's helpful to also adopt consistent social media handles.
Frankly, all that that describes our expertise, call 02 9269 0229 for a costed proposal.