To make your vacation a true rest, choose a package holiday - they use chartered airlines, include transport and accommodation, and may also include a rental car, activities, or outings. They are sold by what are called "tour operators" and to get the best deal, you should consult the websites of various tour operators - there are thousands of different operators all offering competing deals. German TUI AG (which owns brands like Thomson Holidays and Thomas Cook - the inventors of the package holiday, all the way back in 1841), along with First Choice and L'TUR, are the major tour operators in existence today.
To find the best deal, you should see exactly what is offered by various websites. With a little luck you can find great deals for Punta Cana.