Archival DVDs: Inkjet White or Not?


I am about to buy some Taiyo Yuden DVDs for archiving my files. I would prefer the inkjet white TY DVDs over the normal (are DVD’s called Thermal too?) TY DVDs.
The Non-white DVDs are 8x and 30 cents cheaper than the 4x white inkjet DVDs. On the hundred I would save $30 and get double the writing speed with the Non-White DVDs.

So my questions are,
a) are these two DVDs any different in quality?
b) is the extra 30 cents only for the white coat?