Dual layer simply means that it has the capacity to read DVD-9 (dual layer DVDs which hold a theoretical limit of about 9 GB) and unless it specifically states that it "writes" DVDs then it probably doesn't.
Your quote:
"8X DVD-Super Multi double layer drive"
Means that it reads DVDs at 8x and that it can (like any other DVD player on the block) read DVD-9 formatted disks. Else it would have had an R/W (and big bright letters saying it could) to indicate that it can read/write.
HOWEVER...
It gets picky here...
IF THE BRAND is LG and the letters are CAPITALIZED then it is a trademarked phrase that means that it can read AND write in CD, DVD-R, DVD+R, and DVD-RAM formats...
However... If it is NOT LG and it is NOT capitalized or if it hyphenated, etc... You're never really sure without contacting the vendor and/or without having a specific SKU or model to research.
If you would like to tell us what the goal of the laptops is, what they will be used for, and what the price mark is you might find you get a good recommendation or two.
For instance you can get a big-box-store Acer with 1 GB of RAM, an AMD64 dual core CPU, and DVD R/W for dirt cheap. As the quantity is just two that is probably one of the better options but without knowing the real requirements (such as what the reasons are they'd need to write a DVD) recommendations would be silly. More silly considering you can pick up an OEM lappy for about 500 bucks that, depending on your needs, will likely serve for years to come.
