Pretty much all TwinMOS PC3200 now is based on the newer Winbond -CH5 chips or TwinMOS' privately labeled chips. If you can find some (and there are only two places to get it from) with the -BH5 chips, jump on it.
Buffalo Technology is one of the last manufacturers still with -BH5 chips, I believe (Mushkin seems to have the rest). Though, I'm sure they're ready to switch over to the cheaper -CH5 chips now.
Either manufacturer is fine so long as you can find the -BH5 variety. If you can't, -CH5 isn't necessarily bad, it's just not as good as the -BH5.
Phalanx28