Previous employer's 401k rollover to IRA or SEP IRA

Hello, I have previous employers 401k account and possible would like to rollover to IRA account.i have two IRA's one is traditional and other is SEP ira. Does it matter if I pick either one? how taxes are handled when it reaches to the retirement age/qualified withdrawal in either IRA ?. it is beneficial to leave as is in 401k(leaving money in 401k limits my investment choices and fees are heigher )

Thanks