The 2 packages can be deployed in a single task.. You need to ensure that you check the ePO software packages in the following order:
1) Endpoint Encryption Agent for Windows
2) Endpoint Encryption for PC
As of 6.1.2, the NOREBOOT option was introduced and can be used on both packages.. I would suggest only putting this on for the Endpoint Encryption Agent For Windows. This means that the machine will reboot when the Endpoint Encryption for PC is installed/upgraded.
Hope this helps.