Then your draw is over 30" near 31. Draw length always was, before it became confounded, measured at the back of the bow. That was for good reason....what you talked about...the broadhead hitting the back of the bow on the draw.
Your draw length is established by you...not an archery shop. If your arrows have to be 31" so you don't hit broadheads on the bow...your draw length is almost 31" and your arrows should follow suit.
Now...that makes the Howatt Hunter at least 59# at your draw, and probably more since Howatts are famous for being a few pounds heavier than marked. See if Uncle will let you shoot that bow to see if you can handle that. It's only a good buy if you will be able to handle it comfortably.