Quick note, I'm using BL V8.0 and have no experiance of BL before.
Using v7.6, but I assume it would work the same way in 8.0.
I set up an "empty" BLPackage with one single command in it ("echo Rebooting now..." or something like that, it doesn't matter). In the package properties, I set this command to require a reboot. Then, I set up a deployment job to deploy this package and to use the package-specific reboot requirements.
This setup has been very successful with us performing on-demand server reboots.
Search the bladelogic community for ‘reboot script’.