A gold backed Alberta dollar would be optimal but, at present, Alberta does not have any gold reserves. Accordingly, it would be optimal to start off with the US currency or another strong currency that will not be affected by Alberta secession while we build out our gold reserves as well as other precious metals.
It is important to understand that a successful referendum on Independence will massively devalue the Canadian currency, so Albertans should consider the options available to protect the value of their assets and the purchasing power of their money, however denominated. Because everyone has different valued assets and varying amounts of money, each person/family should seek their own financial advice.
Once Alberta is on a firm footing as an Independent Nation and out of debt, an Alberta currency will be instituted and backed by our natural resources, including gold and other precious metals.