There is usually a bookie taking bets on the horses in Shankley's during the day. Was when i was last in Salou anyway. It's pretty much opposite burger king
Not sure where you are staying... but Shankleys or Rovers Return are the best bet for a bookies!
Exchange rate here at the mo is around 1.20... I'd do a deal with Post Office or Eurochange before you come out. I reckon you will currently get a shade over 1.22