Top 3 for me near where you are going are:
The Tossa De Mar - Saint Feliu road. Only done it North to south (hugging the cliffs) , you would have an opportunity to do the opposite and ride next to the sea and have better places to stop for a double cigarette break. (You will need it!) Very tight in places, twisting round cove after cove with BIG drops to the sea.
One other that springs to mind is take a trip out to Montserrat, north west of Sant Cugat. Crazy looking, massive groups of monolithic red rock while all around is rolling hills, with a huge monestary at the top. Get the funicular railway from there to one of the tops for amazing views and more rock weirdness. Great twisty road up and down and through the National Park.
3rd is the C242 which it looks like you already plan to travel on, unfortunately you miss the best bits! From Reus you get a long twisty climb into the mountains onto the plains at La Granadella. Very little other vehicles or people.
Being all Spanish they are all beautifully surfaced, something of a novelty for us Brits.
Have a good trip and post some pics when you get back. Make us all jealous.
