HAProxy will help somewhat, it only passes through full requests, to the SYN floods just get mitigated, and dropped off easily, using little resources.
There is even a special config you can drop in place here. Basically, just have it listen on 80, and your webserver serving up on 81,8080, or some other port.
a bit bout how it can help you, 1st post:
Also uploaded an iptables script that blocks foreign countries, can REM out what you don't want to block: