Modern DVD burners should write CDs fine. The LG GSA-4040B is an inexpensive multimode burner that I have heard good things about. 24/16/32X CD r/rw/read speeds, which for a DVD burner isnt bad. Average DVD burning speeds, 4X for DVD+/-R, 2.4X for DVD+RW, 2X for DVD-RW, reads at 12X (but apparently rips DVDs pretty fast). Also has DVD-RAM support, writes those at 3X.
Its biggest advantage? Price. By a mile, and then some. I've seen this baby online for around $130-140. Newegg has it for $140 including shipping, looks like. Remember that the DVD+ standard has some technical advantages over the DVD- standard, BUT that DVD- is often compatible with more standalone DVD players. So having a dual-mode drive is a must, as nobody in the industry seems too damned concerned with picking a standard...