Very Good..
Any relay that will handle 30A is fine .
I have had good luck with a standard 30A from RS that is short $$$ that I use on different access. stuff and have never had one go bad...
Just make sure the main contacts [ switch section of relay] are rated 30a and the coil [ solinoid section] is rated 12v ..
Remember , a relay is a 'Switched Switch'....it allows a low currect sw to switch On a high current sw. That's it's main function...allowing a large load to be comtrolled ON/OFF with a low load sensor/switch of some sort...