Upgrade MOB for phenomII 965

my present rig is AMD Phenom II X4 965/Socket AM3 (938).
Mob is Gigabyte GA-MA785GM-US2H with 4gb ddr2 PC2-6400.
i need to upgrade to budget mob which has 16gb ddr3 and also supports my current processor(timebeing) as well upgradeable to future amd fx series too.
i use my pc for 3d design vfx task which requires more ram.