Smi, that is the correct burner: The BenQ DW-1655 Lightscribe. You might check if that store has a BenQ DW-1650, as it might be cheaper. The 1650 is the same as the 1655, except without the Lightscribe label-burning ability. The 1650 and 1655 are about the same in producing good quality burns, but it does seem the 1650 is better than the 1655 to a small degree. Because it is without Lightscribe (and if you can find it), the 1650 should be cheaper than the 1655.
Plextor is expensive, and especially in America, Plextor's reputation is very poor, as with the 716a, some U.S. buyers had to RMA (return the drive to Plextor) up to 8 times to get a good burner. Another thing bad about Plextor is that Plextor is very slow about improving and updating its firmware. BenQ will release a new firmware about every 45 days, but you are lucky if Plextor releases a new firmware in 120 days. Also, the Plextor 755 is much slower in standard burning times. For example, a 8x-speed burn should take about 8 minutes, but the 755 needs 9 or more; a 12x burn should take about 6 min., 30 secs., but the 755 needs a minute more, or 7 minutes 30 seconds. So you not only pay more for a Plextor, but you are lucky if you get a new firmware release, and you cannot be guaranteed to get a good, quality working unit. I would basically eliminate Plextor from any consideration because of these reasons.