of the two i would reccommend the platinum because it has a better chipset, i believe that the ultra has a higher bandwidth pci-e slot but i could be wrong, but if that is too pricey then the Neo4-F is fine.
on the ASUS card i hear that the ram sinks fall off easily and that concerned me but if you are careful that should not happen. If that does concern you then this one would put you over budget by a little.