For steady communication for work for a few months, without contract, in Santo Domingo I'd recommend WiMax internet from Wind Telecom, they have 3mb/768k prepaid plan for about 3500 pesos/month. You also need to buy their modem (4000 pesos for stand-alone wi-fi access point, or 1800 pesos for USB stick).
As I understand it from his post, he needs it in Santo Domingo.Wind telecom coverage is very limited, only to Santo Domingo some areas.
.....I can unlock my Iphone 5 before I leave and get a Orange sim card to use there ? How is there a data package with those cards ?