You're really not going to find Lightscribe discs in 100-packs. LS media was a product developed well after CD-R sales had started to slump against DVD media, and was always a niche product. The 100-packs of discs are most often bought by businesses and general-use type users, and that's going to assume lots of time spent burning discs. As such, it's unlikely that a Lightscribed laser-etched label can be added to each disc, given the amount of time required. Even the more-popular inkjet media is still a niche product, vastly outsold by bulk discs (the label-less "shiny silver" discs) and normal branded media.
The only thing you really should consider is price. A normal good-quality CD-R sells for about 25-35 cents (as of 2010, and into 2011), and a Lightscribe disc sells for about 40-50 cents. Now you can still get that price in the smaller 25-count, 30-count and 50-count spindles.
Verbatim LightScribe 52X CD-R Media 30 Pack in Cake Box - $15/30-pack (when buying 4+ packs) + free shipping
http://www.supermediastore.com/product/u/verbatim-lightscribe-cd-r-52x-30pk-spindle
Verbatim 96164 700 MB 52x LightScribe Gold Recordable Discs CD-R, 50-Disc Spindle - $19 each + free shipping on $25 order
http://www.amazon.com/gp/product/B00...SIN=B000V7Y3QE
Note that
Amazon has these labeled as "gold" discs for some silly reason. I can only guess it's because Lightscribe surfaces have that gold/bronze color to them, as opposed to the newer "color" surfaces that Verbatim introduced in more recent years. The actual reflective layer of the disc should be silver alloy, and using a standard Mitsubishi AZO dye (light blue, though more greenish tint due to the disc LS surface).
There are a few others stores carrying these discs, but these were among the best prices around. Hard to beat SMS and
Amazon.