I am looking for some shin guards and gloves for full contact (Kyokushin) sparring. Is there anything I should be looking for / avoid when buying these pieces of equipment?
If you train with an instructor, I'd suggest checking in with him or her - it makes sense for everyone to use the same gear, and there might even be some constraints imposed by any insurance policy or local laws.
If you're mucking around with friends, and you haven't trained in a class enough to know what kind of protective gear works (most of the time), then someone's likely to get hurt anyway....
If none of that deters you, get something you can wash and dry out easily.
These gloves look generally similar to what I use (and used in Kyokushin classes in Tokyo / different brand though), and for gloves I think it's important you can tuck your thumb in hard into your fist, and still open the hand to use the palm and what little grasping's allowed under Kyokushin rules.
These shin / instep guards are similar to the ones I've used.
I've still broken bones on both ends of such gloves, and a kick to knee can still screw you up regardless of the shin pads. The ball and heel of the foot aren't covered by such pads so you "take full damage" if kicked with those. For junior belts at grading competitions people still wear head gear and mouth guards.