need help with vista

Hi everyone im trying to install vista ultimate but im finding it hard to understand whats the difference between Microsoft.Windows.Vista.ULTIMATE.x86.SP1 and vista ultimate 32-bit and 64-bit.
What version is the best and doesnt slow my laptop down thanks guys i appreciate your help
Answer #1
ultimate x86 and 32bit are the same
the 64bit in my opinion is only worth it on a desktop with 4Gb ram +
go for the ultimate x86 sp1, less updates after install