Stock for Stock is the same. Are you wanting a more blue or purplish look? Both are D2S bulbs.
I run 6K in my Turbo and will try out 5K when I get around to it.
There are many brands. Eric at SPP(Supreme Power Parts) is a vendor and I have done business with him and trust his word. I wouldn't pay more than $125-$150 for a set.
Phillips Ultinon 6K might work for you as well.