Need a solution for selling online service,help!

I want to run a online servie selling seo service. and plan to hire 2 contractors to work for me. I want to assign one of them to manage online order and support for customer.another do the offline seo work,but I can’t find a nice script (or wordpress plugin) can meet my need. the first contractor may be allowed to login admin panel to manage the order . but I don’t want him to modify product/service item/price or my paypal account, what he can only do is check the order ,and change their status as new/completed,send notice/report to customer.
I have test many script like wp estore ,wp e commerce,wp advanced ticket system. none of them can meet my requirement…

Usually shopping cart scripts allow to set different privileges for administrators.