Imunify360 is a tried and tested software across the webhosting industry. You can't go wrong using it given the constant updates and new features they're introducing.
It's seamless integration with mod_security and configserver security & firewall make it unparalleled IMHO.
BitNinja has the tendency to cause server stability issues and they're abuse department leaves something to be desired.
BitNinja has the tendency to send abuse reports that are months old.
I can't recommend them in any good capacity.