All you want to know about the scene in Sosua will be found in this forum
http://www.internationalsexguide.info/forum/showthread.php?2227-Sosua-Reports
In nearby Puerta Plata
http://www.internationalsexguide.info/forum/showthread.php?504-Puerto-Plata
The scene changes from week to week so read up on the threads above and keep an eye on them until you leave in Feb.
Essentially, the scene is a bit rough and tumble going to hooker bars, hanging out, drinking beer and figuring out which chica you want to go with.
It can be fun, but is not for the faint of heart.
Dominican women are hustlers extraordiniaire and respect a "macho" man with balls, so if you show weakness they will try you on for size for stupid prices, upsell when you have your pants down etc etc. Not saying you should be an asshole but don't be a pussy. As Russel Peter's dad would say
"Be a Man!"
Also, know that you can buy generic Viagra at the supermarket for about the cost of aspirin. Rest assured that the pills you buy at a major supermarket are not fakes, just generic drugs. Do NOT buy Viagra from any street peddlars/hustlers.
As I understand Canada Customs laws you can import up to a 3 month supply of personal use medication (no narcotics/restricted sleeping pills, etc) medication back with you for personal use.
So, you can bring back up to 90 tablets of 100mg. You can break thin into 1/4's and you have almost 400 doses!
Keep your receipt and include the cost of it in your declaration coming back so you can't be accused of smuggling.