"I'm looking for floppy mini linux with nfs client and dd command"
I doubt that such a floppy could be built because all that software is probably too large to fit on a floppy. However you could build a CD to those specs. Take a look at LifeBoat. LifeBoat is a script which builds a bootable CD using your desktop Linux software. You can add nfs client to your LifeBoat system with a certain amount of work. I think that LifeBoat already has the dd command. If not you can easily add dd.