I have a group of friends in Northern Virginia who start a brewery this year (the submitted their paperwork the day after the shutdown stopped and opened their doors in the beginning of May). They started with a 3 barrel (100 gallons) system and plan on expanding to 20 barrels by the end of the year. To me, this approach makes sense. You minimize your initial investment and let the brewery pay for upgrades. Here in the US, the paperwork and licensing is the same for 3, 20 or 100 barrels. In fact, I think that the difference comes when you're brewing more than 10,000 barrels a year.
My advice, from what I observed, would be to search out what you can get used (if the price is low enough to warrant not having manufacturer backing and having to install everything yourself). Your bottle neck will be in fermenters and bright tanks (also known as a tax tank).