Not really. January it's a rainy month FACT. When the cold air goes down to the Caribbean it becomes water, so the first months of the year up till May tend to be rainy, yes you'll have sun here and there or patches but if you're going to enjoy of the beach and sun, it's better go in fall, and you can get good deals. As well you'll have a higher traffic of tourist during that time as oppose if you go in summer or fall.
If you drive and you're planning to explore the country beyond the confines of the hotel comfort I suggest you to rent a car, the public transportation although reliable it's very limited. Always pre-buy your car rental though Hotwire.com the have the lowest car deals available and usually assign you Hertz or Avis or any of those reliable car rental companies. Once I arrived to San Juan in late night that because they run out of economy cars (which was what I paid for) they upgrade me free.
For lodging La Concha hotel it's not only beautiful but it's strategically located, you can either do high-end shopping in Ashford avenue, there's several casinos close by and you're walking distance to gay venues as well. There are many hotels in the area, but La Concha it's really nice and there's usually good deals if you book in advance. If you guys are in a budget, there's an alternative to rent a house or apt in Condado and splitting the cost between 4 it will be very cheap, as well you can get to cook your own meals if that's your thing.
Hope this is helpful.