HP640B and Ritek DVD+R 16x

I have an HP640B burner(which is actually a Hitachi LG GWA 4162b from
what I can find) and it will burn Prodisc DVD+R at 16x. What I'm wondering is if anyone has experience burning Ritek DVD+R 16x(RITEKR04) with this drive? I guess there's no method to get the firmware write strategy without actually having a blank disc to insert. I'm trying to avoid buying 100 Ritek DVD+R 16x if they will only burn at 8x.

From looking at the Prodisc I think Ritek has a bit better quality control. Trouble is I don't know how to get a 5 pack of Ritek to test before getting 50 or 100 spindle.