problem with the folgertech is that it's american and ships from america. Lots of shipping.
Plus it's aVERY basic kit: does not include either a print bed or a display.

Of the ones you mentioned I'd personal go for the tevo tornado. Just some cool features and a decent build volume.

The he3d kits are also pretty good with quality components and free shipping to most countries: http://www.reprapmall.com/
They even do a triple extruder model for $445

Guess it mainly depends why you want to upgrade ?