Wescot, your old computer appears to be a good one-2 gigbytes appears to be very good.  I believe that Poser states that 512Mbytes of RAM is the minimum so you have plenty.  As for a super hot video card-- 512Mbytes will probably do.  I would, though,  look into a 24 inch monitor that is capable of rotating 90 degrees to take advantage of portrait renderings eg the HP w2408h that has  a 1920X1200 screen resolution.  It sell for $500 plus tax at Best Buy ( just got mine yesterday).   

What you can do is render one figure with hair  and your rendering specs note the time it takes and ask folks here to do the same, those faster than yours, ask for their computer specs.  Jan

For the money you have left over, use it for gas