There are some IDE/SATA DVD writers that perform similarly regardless of the interface such as the Sony/NEC/Optiarc AD-7200A/S. While SATA writers enjoy higher burst rates, some models such as the Samsung SH-S203x series perform much better overall in burning than its IDE counterpart, the SH-S202x series.
Of the two Samsungs you have listed, the SH-S203 is the better drive, and while I don't have any info on the iHAP122 aside from the 22x max writing speed, if it produces burns closely similar to the iHAP/iHAS 120/220 20x series, then the S203 is a better-writing unit.
There are a variety of good writers, but some of the best are EOL or OOS. I commonly recommend Pioneer's DVR-215, Sony/Optiarc V200S/7200S, Samsung SH-S203x, or for a recent and decent overall burner and a drive with a lot of features, the LiteOn iHAS422.
You could try looking for what is available in your area and check up on the various reviews available on the CDFreaks forum since if it's already for sale there's a good chance that someone on CDF has already tested it to bits. You might want to see how your iHAP122 compares to other writers by searching the LiteOn subforum for it and see how people value this drive.
Keep on burnin'!