The way I see it, if you want both the shower head & hand held sprayer to operate at the same time or if you want each one to operate independently, you will need to purchase a hand held sprayer that has a built in shut off button to stop the flow from it while shower head is in use.
>Or, use a three way diverter piped in properly;
1.) To control hand held sprayer
2.) To Control shower head
3.) To control both at the same time