There is NO GeForce 8000 series support for 9x. Period. You will get an error during startup when forcing the 82.69 drivers on 8000 and newer series.
The official 81.98 drivers support only AGP variants of 6000 series in the INF file, not the PCI-E variants, though adding them should make them work.
7000 series is the latest NVIDIA GeForce line working under 9x. (With compromises due to how the latest 82.69 drivers have massive compatibiliy issues, especially with older games)
I have a 7900 GTX and it works under 9x with the 82.69 drivers.
Whoever added those bogus entries for the 8000 and newer series in the INF file (making it unnecessarly large) all those years ago made a huge blunder and now this lie is propagated to this day.
Even though I love my 7900 GTX, I would rather recommend the Radeon X850 series when it comes to PCI-E GPUs for 98SE.
Official Catalyst 6.2 drivers support the X850 PCI-E GPUs out of the box (no INF modifications/unofficial drivers required) and Radeon drivers are I think more stable/have less problems with older games than the latest NVIDIA drivers when it comes to 9x stuff. (not much experience with this so I might not be right)
There's also no issue regarding the VRAM amount as it's only 256MB which is perfectly supported on 9x unlike 512MB on the 7900 GTX (there is a patch for this though). Of course there's also this whole Radeon GPUs are bad at OpenGL debacle...
Of course X850 is slower than 7900 GTX and it doesn't support Pixel Shader 3.0, but for 9x, does it really matter?
EDIT: I think PCI-E GPUs for 9x are not really worth it due to how the 9x drivers are very hit and miss compared to XP drivers for the same cards...if SBEMU matures enough it will make having an ISA retro PC kind pointless for majority of people.
If we lose the requirement for an ISA slot/DOS compatible PCI sound card, we now have a lot of options for cheap/free retro pcs with AGP slots that are more than enough for 9x stuff. Like an Athlon 64 with nforce chip/Pentium 3 with i815 chipset/northwood pentium 4 with 865 chipset/etc, etc...
I really wish Microsoft never extended the 9x support and sticked to the original cut-off plan of 2003/2004 end of support.
After the Service Pack 2 released for WinXP, 9x should have been killed...we wouldn't have to have all these hodgepodge drivers...
I've been doing 9x on modern PCs/GPUs stuff for many years and there was always some kind of compromise that makes it not worth it in the end...it's a love/hate relationship.