Looking for "good" girls? One week in a tourist spot? Probably better to check out one of the other websites designed for that sort of information (I will send you a PM) and read, read, read ... ask questions .... and read some more! You will find out what you want to know!
Do you speak any Spanish?
Do you know what goes on in a "tourist" spot ... and how YOU will be seen there?
If you stick to your plan, you may find that your best bet is to party with other tourists (girls on vacation), given what you are looking for.
Good luck