soultribe

I am currently using an Ipod touch( 8gb) > ATHS5JN ( modd with canare L282AT). so planning to upgrade. i listen to 50% rock,blues.. and love wide soundstage, decent bass. i found i got a 5th Gen video Ipod lying around, but batt flat. and looking at the forum i read, it seem the inner DAC is good , i don need anymore external DAC, but jus get a portable amp? my budget is around $400 for a new headphone + amp. wat do you think of ATH M50 or second hand H600? many advices needed thanks