Ask pjiang and xiaobaitu

I am applying NIW. Do I have to submit employment veryfication letter with my I-485 form? My lawyer told me I just need paycheck stabs for the past 3 months and don't need the employment letter. I am holding J-1 visa and it will expire in february 2008. If I submit a employment veryfication letter, should it provide a permenent position or the job end in next February is ok?
thanks.