Citra but yung Chinese Builds, di pa perfect yung emu but more stable yung Chinese Builds of Citra.
As for the ROMs, note lang po na "decrypted" rom ang needed pag emulator, search nio lang dn po, for example "decrypted Pokemon Sun."
Kung pokemon lang lalaruin nio sir dont download X/Y for now kasi sobrang buggy nya, go for Sun/Moon then OR/AS.