Your maximum SEP contributions are based solely on your net incomes from self-employment. You can't consider the other wages. Details are in IRS Publication 560.

Thanks; what exactly counts as self employed? The outfit we are working for pays us as contractors, I assume that suffices?

Also, are there any special steps one needs to take to set up a SEP-IRA? I am only able to find Roth/Ordinary IRA account applications at various brokerages..

Thanks,
Sam