Default Can every Xoom model run 4.4.2 ?

Hi, my kid wants a tablet, and i want a cheap one as this is gonna be his first one, ive found a guy that sells his Xoom for a decent price, myquestion is, can i flash custom ROMs on every Xoom model? cause i have no idea what model is the one i wanna buy, also how good is the performance on 3d games? he wants to play some 3d soccer game with cartoon network characters.

forgot to mention, it is running 4.0, dont know if it is stock or custom though.