400w HPS conversion bulb?

Hey! I currently have a 400w metal halide ballast, and I am about to put my jack herer into flowering. Do you know where I could find the best deal on an 400w HPS conversion bulb? any trustworthy sites?

Thanks for any advice

I have myself a 400W HPS Conversion lamp. What a difference in flowering compared to my 400W MH. As for a good site..hmm got mine at the local hydro shop, but I'll have a boo around..

Oh ya, just remembered.. I have not used them, but it has received many great reviews from people here on RIU: http://www.htgsupply.com/

GL