Hks made by Garrett to Hks specs, so made in USA, ball bearing turbo, say $3000 for a kit.
KKR made by KKR in Korea, bush turbo, say $800 plus water/oil lines $250.
Give or take a few $$.
If your poor, and don't intend keeping the car - or inversely the turbo - forever, go the KKR.
If you can afford it go the HKS, its like comparing an excel to a corolla, you get what you pay for.
HPI had a write up on the KKR a while ago, issue 84.