I've used maple with heartwood in it, and after staining, the difference between the sap and heart disappeared. But I suppose if you were after a light color, you'd see the contrast.
Quarter sawed is nice, but over rated, and plank sawed is just fine. You need a big log for quarter sawed stocks without any heart wood.
If you're making a high grade very specific gun, and it needs a certain grain pattern, then this log may not be for you. I bet you'll be able to get some good stock wood of it. Just avoid the heart in any stock(the very center of the tree). Wood on either side of center is good to use. Cut your planks, and immediately cut stock blanks from them. Paint the ends with any kind of paint, old latex is great or Titebond glue, keeps the ends from splitting.
Stack the blanks out of the sun and wind, with stickers between blanks and lots of weight on top. Cover lightly with a tarp for the first few months of drying, then uncover.