Many will say, the longer the bow, the sweeter and more consistent you will be with it. Especially for target shooting. I am a fan of shorter bows. Primarily because in hunting situations the longer bows tend to get in the way of tree stands, ground blinds, sticks, twigs and other noise makers that may spoil the chances of meat on the table. Also, I'm kinda short myself. A short bow fits me better.
Along with the others, it's personal preference. Of course, this isn't the only bow you'll ever make, I presume. Make some long; make some short; make some inbetween. You'll discover your personal preference and gain a bunch of experience doing it.