I have asked about this before, please search my posts as Esenthel already answered.

If you need dx10+ features, just use the 32bit version. If you wait for a 64bit DX10+, you will only delay your work.

i've found it here but i will know the performance comparison and the real difference

It will be difficult to see the performance difference between the two. What exactly do you need the 64bit DX10+ version for? How much performance difference are you expecting the 64bit to have over the 32bit? What do you think you won't be able to do with the 32bit that the 64bit version can only do?

just for knowledge