Questions on SMP and 64 bit

[Joseph Vella]

I'm buying a new computer, and am thinking of the new dual core AMD X2.  
I'm not sure I want to run 64 bit kernel yet, because of driver support and things like flash, and video, etc..

Will this processor still be as fast as a 32 bit if I use i386 kernel?  
Do I have to use a SMP kernel?  
Is there one available for i386?

Should I just get a 32 bit single core, if that's the kernel I'm going to run?

The main things I want that I don't think are easy to set up would be flash, mplayer and nVidia 3D driver.