I think your on the mark, the difference between Live! cards is marginal in real world, if you already have one I wouldn't go out and buy an earlier card.
128MB would be max ram in a PC, but again down to cost not because it wasn't possible, I wouldn't loose sleep over having 512MB
Here were the 2 PC's in our household as reference
Very close to my PC I got new in late '98
P2 400 (Couldn't afford P2 450)
64MB RAM (Plenty back then, but agree 128MB is reasonable for high end)
TNT 16MB (Voodoo 2 was an option but TNT was the better buy)
Onboard SB PCI128 (but did dream of the Live!)
10GB IDE drive (SCSI should at least be around the same size)
and rest of the families PC they got in 99 which was more budget then mine
P2B ZS
C500 on slocket
TNT2 M64
SBLive! Value
8GB HDD IDE