Welcome to the forums, flyproductions!
@paulwgraber
I'd like to add that there is a compatibility list at themacelite, were you can look which 9800 "PC"-Cards are good to flash (as far as you do not just look for the reference design). Some have different Memory and - I guess - two models are quieter, because they have a heat regulated fan (but they seem rare).
Did you tell us in the other thread, whether you also plan to use it in OS 9? I do not remember atm. The 9800 works in OS 9 but 3D Hardware acceleration is not supported and so some games have problems (Had that experience with a flashed 9200. There are 3D drivers for 7000/8500/9000/9200, but, if the card is a flashed card it won't work, as I was told. For the 9000 there is a guide on how to solder something, so that 3D acceleration for flashed cards from the 8500/9000 range are supported. For the 9800, though, ATI didn't make 3D drivers for OS9, so it won't work for some OS9 games, anyway (even, if there was to solder something).