By mod I assume you mean flash the DVD drive- for hard drive modding purposes I think everything works.
What sata chipsets work depends on the drive you are flashing. Via 6421 (and 8421 I think) work for all drives.
Some of the Nvidia nforce chipsets work on all drives too, some of the really early ones do not though. I think it is nforce 3 and 4 series (1 and 2 not working) but I am not sure of the specifics at this point in time (it should be in a good guide though).
You can buy via 6421 cards for not much at all (if you can not find one for around $15 USD you are not looking hard enough) in either PCI (internal PC cards) or PCMCIA (for laptops) formats.
Some drives are less fussy and the only ones you can brick in flashing are hitachi so it is worth a spin with what you have sitting there. Equally it is not necessarily the case that the chipset does not work but it can be drivers as well. That is to say you have a working chipset, even via 6421, but the drivers will mess things up so consider being able to drop down into DOS (and use dosflash + firmtool and the like) or nuke the drivers (should be in flashing guides like the one that is on the jungleflasher site).
Others still have workable setups and fail to get the drive into service/0800/flashing/tray half open mode so make sure you have that on lock too.
Between via and nvidia they have a fair bit of the motherboard market but the other big player is intel and much like graphics chips they have the ears of the cheapo (and occasionally not so cheap) OEM computers.
Before you ask
http://www.cpuid.com/softwares/cpu-z.html (downloads on right hand side) will tell you what you have.