Havent had them so comments are general... typically you would serve a light to medium red first but both of these look like powerful reds... ripasso would usually be served last so on that basis the gran reserva should go first.
Of course a lot depends on if / what food is being served.
Next time keep an eye out for a rioja crianza, merlot, pinot noir or red burgundy so you have sth lighter.
"To follow knowledge like a sinking star..." (Tennyson's Ulysses)
