Personally, it sounds like you are fairly inexperienced at archery in general. If this is the case I would highly recommend that you don't buy a Mathews or any other bow that is limited in it's adjustability for drawlength. You will have ample time in the future after you learn from shooting what your optimum drawlength should be. And I can all but guarantee that it isn'y going to happen by walking into any shop and getting measured, unless you happen to run into someone who is really, really picky about it.

I'm not saying you can't get close, but there's just no reason to spend so much money, for something that may not be right just because you heard from someone, who was told they heard that Mathews is the best bow out. The truth is the best bow is one that you can shoot the best, and this takes a long time of trying to perfect shooting form and little or nothing to do with the bow itself.

I would get into a shop and shoot a lot of bows before making a decision. Believe me, there are a lot of bows on the racks from $300 to $500 that will shoot every bit as good as the $700-$800 models. Of course, maybe you won't get invited into the Mathews clique, but who really cares.