Here is some information I found for you on the Pacific Digital:

The Pacific Digital 8x DVD±RW uses rebadged LiteOn (LDW-851S/LDW-811S), NEC (ND-2500A) (Writes both 8x +/-) and BTC drives.
(Serial numbers starting with a "41 and a letter" are reported to be NEC ND-2500A drives)
(Serial numbers starting with a "P" are are reported to be BTC DRW1008IM) drives)
all other numbers are LiteOn drives.

Currently right now, from most user reviews, the Pioneer 108 DVR-108 or the NEC ND-3500A are the models of choice right now. They both run around $70-80 at Newegg for OEM models. After flashing them with new firmware, you should be capable of doing dual layer burning on supported media. They are both 16x DVD+-R/RW drives. The major difference between the 2 are CD-R speed, with NEC at 52x and Pioneer at 48x, which really isn't much of a difference. Both are excellent drives. The Pioneer is virtually silent. I have that model and I love it.

The Lite-On, from past experience, is usually a little louder, and they have a longer load up time. It is still a good drive, and can be flashed for Dual Layer burning, but their best model right now would probably be SOHW-1633S, which will cost $70-80, too.

For DVD media, from reviews and experience again, the brand to get is the Ritek Ridata 8x. This model is similar to performances of the Fuji's, but the Fuji's cost a bit more. The best media to buy is Taiyo Yuden, except they are extremely expensive. I prefer DVD+R over DVD-R. Both have their advantages and disadvantages, with DVD-R media being a little cheaper. A 100 pk should cost around $40-50 for the Ritek 8x.