Avoid anything but the usual top quality DVD’s. (You’re stuck with purple). If you want the project to make a positive impression, having the discs actually be readable in a variety of drives is the best approach. For that, either DVD-R or DVD+R with bitsetting to DVD-ROM.
Nothing will make a worse impression than having the discs returned cause they won’t read.
The MAM discs you cite will use the same colored dye as any other. It’s the reflective layer that’s gold. So, the gold color will be most visible from the back. The recording side will be slightly different, but not hugely.
Also, given the physical structure of a DVD, compared to CDR, MAM’s claim that it will last longer than silver is highly speculative.