Ric, the blank is about perfect size, for what you are wanting to do. I don't know if there is a, rule of thumb, for the angle, but what feels best to you is what it needs to be. Fitting the action and the front stock screws are the hardest part, but as Sean has said the holes can be fixed. You have to be careful on inletting, especialy for the cocking arm, to deep and it won't cock. I would fit the action to a scrap 2x4 for practice, then when the fit is right, use it for a patern. Also I would fit the action to the blank before I did much shapeing, so you don't spend 30hrs shapeing only to mess up on the inletting. I have made only 1 stock and all I used was a small router, chisel and a moto tool. Most of the fitting of the action can be done with a router, then square up the back with a chisel. I hope some of this helps.
Mike