Should I install 64bit version of Ubuntu?

Hello,

I've got an XPS 410 with a 2.13 Ghz Dual Core CPU and 1.5Gig MB of RAM and was wondering which version of Ubuntu should I download. Is there any advantage to installing the 64-Bit version? Is there a disadvantage to installing it? Which one would run faster? Also, I'd be installing in through VMware and I'm running the 32bit version of Vista Home. Is there a conflict with the 64bit version of Ubuntu?

Thanks,

Jeff