What everyone has said. Start with a lighter bow than normal. I started with 40-45#ls at 28 and have been staying with those weights. even afetr a 3-d I start to feel it.
Try as many as possible. Try to locate a club or go to the events listing to see what is close. I was fortunate enough to meet someone with 28 different bows on his wall living close by.
The great thing about the classifieds here is, if you buy a reasonably priced bow and take care of it, you should be able to get close to what you bought it for. Also , many of the posters are well known and usually will answer all your questions. Other sites are more focused on moving products.
Good Luck and enjoy the search.
The lower weight and the try before you buy may be the best advice you will find.