What is the best strategy to prevent someone from stealing our technology pre-patent?

The time taken from filing a patent application to patent grant typically ranges from 4-6 years. However, from a commercialization perspective, you should note that you do not have to obtain a granted patent before you can sell/commercialise your invention. Commercialisation can occur after you file a patent application for your invention. As such, the length of time taken to obtain a granted patent should not impact on your ability to commercialise your invention. A grant patent simply provides you enforceable rights to stop others from exploiting your invention. As such, if you discover someone exploiting your invention before patent grant, you could take measures to expedite patent grant in order to take action against the alleged infringer. In most jurisdictions, you may be able to claim damages back-dated to the date the patent application is first published.
With regard to your question about different forms of IP protection, you should consider trade marks (for protecting your brand), design patents/registrations (for protecting the visual appearance of your invention) and patents (for protecting the functionality of your invention).