My advice is ussually the following go with wichever is the cheapest in your region. Both should work great and with ballistix your almost certain it will be compatible.
Specify what motherboard youll be using, it could make a difference.
Asus P4P800DX, P4C 2.6ghz@3.25ghz, 2X512 OCZ PC4000 3-4-4-8, Leadtek FX5900 w/ FX5950U bios@500/1000, 2X30gig Raid0