You could also look at using a thyristor block. They are more expensive than triacs but can switch currents in the several hundred amp range.

A common trend now for high current switching is to use two devices in parallel, generally a relay which has long term current capacity and an IGBT which are great at absorbing the high in-rush. The IGBT is switched on a fraction of a second before the relay to handle the in-rush and avoid the contacts of the relay welding and when the load is switched off the relay is switched off a fraction before the IGBT so the relay contacts don't draw an arc.

Happy switching!
Tony