Re: Opening number
Assuming you're playing to a British audience, you can't go wrong with classic Kinks: All & Day & All Of The Night or You Really Got Me, or something a little mellower like Well Respected Man. Or, how about some Van Morriason? Domino, or the mellower Moondance.
Those are the first things that popped into my head, there are certainly hundreds of great hits from the '60s & '70s, from various countries, that have broad appeal. Most of the US r&b hits of the '60s hold up well: Mustang Sally, Midnight Hour, Motown & Stax stuff, etc.