My first question would be who makes it. I don't know that much about Hyundais so I can't comment on how hard it would be to mount.
But 190A alt for $150 sounds a little fishy to me. Most high output alts used in high end audio system cost will into the $500 to $600 range. Is this one used? What brand is it?
Side question what kind of amps are you run that makes you need a 190A alt?