Barcelo Bavaro Beach and Barcelo Bavaro Caribe are two separate hotels within the same Barcelo Bavaro complex. What your touroperator's listing may indicate as that you can be put up in either of the two hotels. They are of the same category and offer the same srevices, actually, they are next to each other. Personally, ask for Beach, it is more central than Caribe.
The hotels are 4* hotels, each room has TV, AC, minibar. Don't expect Ritz but it won't be Sleep Inn either. You will have access to other hotels' services within the complex (Casino, Caribe, Beach, Golf), with the expection of Palace services.
If I am not mistaken, Beach has various buildings, while Caribe has one large single building. There is no difference if you are on the first or third floor, the only dofference may be the view, and all rooms are the same. I think all buildings are 3-stories high.
You can activate Orange GSM card, but to do that you will need to go outside of hotel. The closest city is Veron, which has Orange dealers. You will need passport to activate the card, the cost is RD$ 350. About 11 USD.
You will get RD$ 100 call credit, you can recharge by purchasing rechargable cards at most colmados, and also most probably also within the resort. Credit card recharge is not available.
Your phone must be able to support 1900 MHz (it must be a triband or quadband phone).
There is also Codetel/Claro GSM, but right now foreigners with passports cannot activate prepaid GSM account. Moreover, Claro's rates are higher than Orange's.
Here is the link to Orange (in Spanish)
Orange Dominicana
The calling rate to Russia is approximately US$0.40 per minute with all taxes.
A RD$100 card (US$3) will give you about 7.5 minutes of calltime to Russia.
You will be billed at 1 second increments after the first full minute (for international calls) and 1 second increments from start for national calls. You do not pay for incoming calls.