right now, there are o.e tunning, Ionperfomance, APC, WW, and DG.
o.e tunning, Ionperfomance are authorized vendors in this forum
they are cheaper than DG good luck
I also heard APC makes good CF too.
They have 2 different kinds of CF
3K and 6K
obviously 6K is more expensive, but they have decent price, I think they are reliable company.
It's your choice. good luck my friend
good luck