Laura, welcome! I am also from Seattle and also lived and worked in Valpo/Vina so we are cut from the same mold it would seem.
There are so many boliches to choose from it's not even funny. If you want to go dancing some time send me a PM. Here are a few ideas to get you started.
Mint. It's expensive to get in but there are usually lists to get in for free, and it is a trip. It's near the Jorge Newberry airport, plays all the music you describe, and has a huge outdoor space for cooling off and watching the sunrise.
Bahrein has a great vibe, different floors/rooms with different music. Their website seems to be broken at the moment.
On Wednesdays,
Operatown has an 'after' which is like a happy hour that starts at 7, goes until late, and plays your kind of beats. Be sure to put your name on the list. Shamrock also has one on Wednesdays, I think, which is a little more electronic-oriented. Also note that although Shamrock is hoppin just about every day of the week, it's in the heart of Recoleta and therefore filled with English speakers if you're trying to avoid that crowd.
I seem to remember really liking
Wet (top 40 and cumbia I think) but I haven't been there in over a year.
On Thursdays,
Niceto Club has a party called Zizek that's supposed to be great.
On her blog, Amy describes a place called Sabbia in Barrio Norte that sounds like it's worth checking out.
In general, just about any club you go to
tiene lo suyo. The key is to always find out if there is a list and if so, get on it! If you're a woman there's really no good reason to pay to get into a club here, or at least not full price.
Again, welcome!