Dice three of the garlic cloves, saute in EVOO until lightly browned. Cool.
Finely dice tomatoes, mix in bowl with EVOO, garlic, and balsamic vinegar (if using balsamic vinaigrette, use here instead of balsamic vinegar).
Slice basil into strips, add to tomato mixture.
If using cucumber and red onion, dice and add in here.
Season with salt and pepper to taste. Cover mixture and chill for at least one hour.
To prepare toasts, slice bread into ⅓" slices. Butter, season with salt and pepper. Broil until lightly toasted.
Slice fourth garlic clove in half, and rub cut-side down onto toasts to infuse garlic flavor.
Slice fresh mozzarella, and set out with parmesan and softened cream cheese.