If you don’t have Meyer lemons you can substitute 3 tablespoons of lemon juice plus 1 tablespoon of mandarin orange juice (or any other sweet orange) for the Meyer Lemon juice. The zest and slices of regular lemon or oranges will work fine.
When mixing the rub, try to use no-salt lemon-pepper mix. If you can’t find that, cut back or eliminate the extra salt.
I do not recommend purchasing the pre-marinated pork tenderloins that are available in the meat department. First, they are generally high in sodium content and secondly, you want to control the flavor profile of your dish.