Beside the well known DID RK, I have recently fond some funny brand in the local market,
KISS, DC? The dealer told me KISS is from japan and DC is from euro? Both of them are
fairly cheap.

Does anybody has any idea about them?
Should I give it a go?

Cheap chains mean nore stretch and more frequent adjustment. If you get it just be prepared to spend lots of time pulling chain maintenance. I put a cheap chain on the GS and I kid you not I have had to adjust it every 300 miles and it is time to replace it after only 4,000 miles.

I have a high end o-ring chain on the 954rr and it is averaging 2000 miles between adjustments before it's slack is out of spec.

Buy the expensive chain. Take care of it properly and it will last much longer.

they told me that both of them are o-ring chain.

In fact, I need to get the sprocket changed as well, which brand is good?

the rk excell chains are wicked, they do coloured chains and alot of superbikes run with them, if you can get a rk chain for cheaper than another brand i would defently go with it.
do a search on the net im sure you'll find some info on the chains. 

I'm not a very big fan of Oring Chains.I tried one on a Bike Once (RK Takasago) and I just had One Problem right after the othe with it Flying off..I change to a Regular Heavy Duty RK and it stopped.I had a Link to a Website that Specialized in Chains and they had this Big Section on not buyng an Oring Chain even though they sold them.
Any Heavy Duty RK,Regina or D.I.D cain is best.Don't buy a Cheap Chain.A friend of mine done the Iron Butt on His Kawasaki Triple back in September to the Deals Gap meet from PA and had to Change Chains several times during the Whole Ordeal.