Ohh sexy grandma
Did not play very much with voodoo cards at all so can´t help at all there.
What i would do is look around for a IDE to CF (compact flash)/IDE to SD/IDE to SATA adapter (and an ssd) and use that instead of old spinning rust.
Compact flash have enough space for win98, SD cards have more and are probably cheaper/easier to find.
Sata ssd can be even bigger but can not use more then 137GB anyway.
Win 98 can handle max 64GB drives, Win 98SE (SE=second edition) can handle max 137GB drives.
I see no reason to use 98 over 98SE!
Now changing to flash based storage do have some problems and some advantages.
1, Wearing out the flash memory!
The smaller the drive the more this will come into play and is one reason to skip compact flash (since they are smaller).
2, Quality off the flash memory!
SD cards will often have the memory chips left over that was not good enough for anything else (probably true for CF too nowadays).
SSD will most likely have better memory chips and probably is faster.
Then again if your using a big 512gb drive and use around or under 10GB it will not wear out particulary fast since the SD/SATA controller do use the entire drive for wear leveling.
Partition size does not matter here only the space that is actually used!
3, Speed!
The IDE bus do top out at 8.3 MB/s maximum originally later 33, 66, 100 and 133 MB/s.
In this case probably 133!
I have read that older adapters (and maybe some never too?) can't max out the IDE bus but even then it will feel like the system is faster since no seek time for every file read/writen, only when moving large files will it be slower.
All in all i would look at 128-256GB SD cards or an SSD for a bit more money.
Och just nu 2sek innan postning så märker jag att jag skrev allt detta på engelska arrrgh!
Om du inte kan eng så google översätt!
Hej ingen fara anledningen att jag kör IDE hårddiskarna är enbart för känslan (och det obehagliga ljudet, jag vet att jag kan få ut detsamma med som du säger CF men är väl en nörd). Samt ursäkta att jagi nte var tydligare jag kör Win 98SE