Dual boot on 64/32

[nenin]

I`m preparing to move on Gentoo 2004.0 AMD64 from Gento 1.4-Athlon. I`m not sure that all will be OK with my soft so I wish to leave both versions on a different partitions. Questions:
1. As I understood, for AMD64 I need grub-static. Does it works OK with Gentoo on kernel 2.4.x buided for Athlon?
2. Other issue- I`d a lot of problems with Radeon 9200SE and X. How it works on AMD64? I probably do not need any 3D, but I definetly need X to run Mozilla and IDE for C++/Fortran.

Hard: Athlon 64 3200, 1 G RAM, ASUS K8V, normal IDE (not a SATA).