From cross_stix on our forums:

Since the announcement of C4Evas DVD Burner FW I considered I would begin a thread about the re-badged iHASx24 B drives, as the Lite-On badged drives may become harder to find.

Buying a re-badged drive should likewise guarantees you a Mediatek chipset based drive (An or B series). Whereas purchasing a Lite-On drive, you could besides get a NEC chipset drive (Y series, re-badged Sony Optiarc AD-724xS/AD-726xS)

* Confirmed iHASx24 B re-badges
(thanks to Exobex for 1270i and PL-L890SA)

-Asus
DRW-24B3LT (confirmed)
DRW-24B3ST (confirmed)
DRW-24B1LT (confirmed newer drives are B chipset, older may be A chipset)
DRW-24B1ST (confirmed newer drives are B chipset, older may be A chipset)

-HEWLETT PACKARD (HP)
DVD 1270i B (confirmed)
DVD 1260i B (confirmed) there may also be older A model (unconfirmed)

-PLEXTOR
PL-L890SA (confirmed)

club.myce.com
Now the A series drives are no longer produced so your chances of getting an A series drives from a retailer such as Newegg is slim. Looking at reviews on Newegg for the DRW-24B1ST, there is one dated back to March 2011 reporting a B series drive.

* Crossflashing any re-badged iHASx24 B to Lite-On firmware (Thanks to Spark for procedure)
Utilities and Lite-On iHASx24 B firmware can be found here
Personally I would recommend iHAS624 B firmware for LightScribe drives and iHAS524 B firmware for non LightScribe drives as this gets you the largest feature set (SmartErase + LabelTag), but you can chose any iHASx24 B firmware you wish.

Process is:
1. Launch EEPROM utility and backup EEPROM.
2. Launch Firmware utility and backup Firmware.
With the above steps, these dumps will be necessitate if you ever need to return the coached to stock for warranted repair etc so it’s a good idea to make 2 dumps just to be sure.
3. Flash the drive using the Firmware utility selecting the exe file. All settings should be leaved as default. (note: unscrabbled c0deguys firmware is necessitating)
4. After the Flashing utility confirms that the flash is successful, power cycle the drive. The Green activity LED on it will now twinkle constantly but the exclude button etc should respond as normal.
5. Run the EEPROM utility and launch the Convert option. This will finalize the cross flash process.
6. Once this has completed successfully, power cycle the drive again.
7. The coached will now be recognized as an iHASx24 B model and the handle is now finished.

Note: Once cross flashed with c0deguys firmware, you should be able to use official Lite-On firmware updates

Source: Xbox-Scene Microsoft Xbox News