your options other than cornies are the more commercial centric systems based generally on a sankey S fitting,
the main difference between the 2 types corny vs sankey is that sankey kegs dont have the wide opening for a lid and contain beer in and gas out through a single double purpose connector. And Sankey kegs dont generally have PRV's on the keg.
the spear removal of a sankey keg Can be dangerous if all the internal pressure in the keg has not been vented, when unscrewed the spear assembly can become a projectile if the keg is under pressure which could be lethal..
sankey kegs come in a few flavours there are a few single use plastic options some of which can be reused, some not, atm i think its only brew uk that stock the 20l slim sankey kegs, afaik crusader stopped selling to the public? 30 and 50l options are the more usual squat broad keg shape.
benefits of sankey kegs are less seals to fail, and no pressure is needed to seal the non existent lid
cons include more expensive couplers, without a prv on the individual kegs a regulator equipped with one is wise where a cheap welders reg works with cornies, the cost of a spear removal tool and over-coming the safety features.. and the SS versions of the kegs are more expensive both new and 2nd use.