As a load balancer, haproxy is usually what you want. It has more tools in the bag for those use cases.
As for performormance, my experience is that haproxy outperforms nginx in the load balance cases. You have to go out of your way to configure nginx to get close.
Here's an interesting comparison:
https://www.loggly.com/blog/benchmarking-5-popular-load-bala...
