The US and UK options are at least workable to fly reasonable light twins, which affords extra piece of mind, safety, and lower stress in some situations. 2000kg you can't even fly a Seneca, so stacking 6 pob into heavy singles is the only way you'd get 6 on board anyway. 2700kg allows actual 6 seater, and more capable 4 seaters. I don't think you need to go all the way to 5700kg, but definitely closer to 3000kg would be the right area.