Buona roba and buone cose are Italian equivalents of the English phrase "good stuff." Context makes clear whether the reference is informal and inclusive of drugs (case 1) or translated literally as "good things" (example 2). The respective pronunciations will be "BWO-na RO-ba" and "BWO-ney KO-sey" in Italian.
"Good" in English is buono in Italian.
"It is good!" in English is È buono! in Italian.
"Good night!" in English is Buonanotte! in Italian.
"Good! And you?" in English is Buono! E tu? in Italian.
"Good! How are you?" in English is Bene! Come stai? in Italian.
"Good food!" in English is Buon cibo! in Italian.
"Good health" in English is buona salute in Italian.
"Good head!" in English is Buona testa! in Italian.
"Good artist!" in English is Buona artista! in Italian.
"Good fortune" in English is buona fortuna in Italian.
"Good lover" in English is buon amante in Italian.
"Good vacation" in English is buona vacanza in Italian.