Unsure of what your current build is. You say it was old spec --- from general stand point ---- for a new build running vista --- I would recommend at least 2 gigs memory--- hard drive seems short on space at only 80 gigs --- not much difference in cost to go to 250 gig or 320 gig --- a 7600 video card might be better.
With that being said, if this is new build see nothing stopping from new build using vista. With regard to actual performance scores of your system, I would not know as your specs are somewhat unclear.