Can't offer any advice, but I have what I consider to be a modest mid- to low-range system (Windows XP, Athlon XP 2000+, 512MB RAM, 120GB hard drive), and was recently able to construct and render a scene containing:

six characters -- the DAZ Charger and reindeer, Penny, a modified version of Victoria, and a couple of custom-made figures

additional figures like the DAZ Sleigh, reins, and reindeer harness, conforming clothing for Victoria and Penny, my conforming mane and transmapped tail figures, and the DAZ Cyclorama

Over a dozen props, including a dynamic clothing item I draped over the Charger

And I made use of displacement, specular mapping, and other advanced features, also. It took a while to render at 1600x1200, but it didn't choke.

P5 couldn't render the scene under Win98, but under WinXP handled things nicely.