I recommend purchasing a bow offering either speed wheel or single cam eccentrics. Despite what your might here, or assume because of how different they look on various bows, there is little variation in performance from one type of riser to the next. Again, a riser is the handle portion. This forces you to pull the string further back, which in turn holds the string on the arrow for a longer period during the release, resulting in more velocity. Some inexpensive models with straight risers are difficult to tune.
Limbs are the final primary bow component.
Limb selection should be the least of your concerns. Most entry level to intermediate bows have limbs constructed of molded glass. Higher end models offer limbs made of carbon and other composites. But for the average hunter, the increase in price of jumping from glass to carbon does not justify the benefits gained. Some inexpensive bow cables are anchored on only one side, creating a significant balance problem.