The HTTP/HTTPS monitor template is effectively checking availability if that is an option, too.
HTTP monitor may work in some cases although ICMP (ping) traffic is principally different from TCP and HTTP ones, I heard. For my purposes, I use TCP monitor (basically port scanner) to check if a specific port on a target is open. Adding an ICMP monitor may help figure out if the target is down, or got firewalled - given that ICMP traffic (if allowed by the target) is considered the most benign.
