*) Sony 300A = 48161H with a Sony label slapped on it (many of Sony's drives are manufactured by LiteOn)
*) Sony 320A = 5232K (LiteOn's 52x combo; the older sibling of the 48161H) with a Sony label slapped on
*) 48161H = my favorite
*) 5232K = since the 320A was on the list...
Can't say much about the other drives, but I would definitely recommend the LiteOn drives (or the Sony drives, as they're really LiteOn drives) for these reasons:
1) LiteOn is the undisputed king of CD burning quality (if only their DVD burning were as good)
2) LiteOn drives last a long time
3) LiteOn drives seem to do have better error correction and can read DVDs better
4) LiteOn drives can do EFM-encoding correctly (for copy protections)
5) You can use KProbe
6) There is an abundance of resources and hacked firmwares for LiteOn drives
You can also read the CD Freaks review of the 48161H.
As for the 48x combo vs. 52x combo, that's really your personal decision. Note that 52x burning isn't that much faster than 48x burning, and you'll save yourself only a few seconds. And 32x CD-RW media is expensive and hard to find. So I don't really see that much of a gain to be had from the 52x combo, but that's just me. If the 52x combo costs about the same, then I'd get it, but if it costs significantly more than the 48x, I'd get the 48x.