Reply to VMS4 and NI Audio 2 ?

Hey guys, I am about to buy an American Audio VMS4 and I was believeing of getting sound card because of so much hearing of the VMS4 low Db and quality incorporated soundcard...
but not wanting to spend too much money, I would like to know wich kind of sound card should I get?
my supplier don't have the NI Audio 4, but I was believeing if the NI audio 2 wouldn't do the job? what else could I get for less than 300