Hi MaryKateW, I would try both bows out to compare them and see what your preference is. Some people like to own both a heavy bow and a light bow to provide options depending on what kind of music style they are playing. I prefer a light bow as it makes it so much easier to do techniques such as spiccato. I tend to play heavy, so I would not need a heavy bow. But if you have a lighter touch, you might appreciate a heavier bow to help you sink into the strings for a more pleasant sound.
When you try the bows, play a variety of styles with each bow, going back and forth between them. You will want to play high notes, low notes, any bowing techniques you know, sustain tones, short notes, etc.