Torre Veirmar (number 1..there is at least one other) is next to the Hotel Intercontinental. Not really walking distance from Piantini, probably a 150 peso taxi ride.
Looks like a nice place, Ive never been inside. There are several new-ish Miami Beach style glass towers along the malecon...take a nice long walk and check them all out...bring a camera and take notes on each one...