The 800 numbers work from all over latin American but they are not free. An operator will come on the line and explain that you will be charged for the call and to hang up if you don't want to pay any charges. Puerto Rico may be different because it is an American territory. Bottom line the 800 numbers work but they may not be free. Natrually it would not hurt to get the international numbers for all your outs because anything is possible. My guess is you can call 800 numbers from PR but will have to pay regular charges (so much a minute). Some books will let good customers call them collect if you set it up in advance.
Best of luck and enjoy the vacation, wil.