If you can make a 50+ break with a certain cue, there's no reason why you shouldn't make a 100+ break with it. If they need a new cue, what the top players do is pick a cue they like and can make breaks with, and stick with it usually for at least a month or more. Some professionals have used the same cue for many years. The cues they use are generally, but not always, about 18 ounces, quite solid and not whippy, 10 to 10.5 mm tip size and are made from either ash or canadian hardrock maple. Ash is the most popular wood. Pick a cue and stick with it for a while, and you should start making bigger breaks and start playing at a higher and more consistent standard in general.