i'm looking for a japanes maple that has leaves the same as sangokaku - but grows out in an umbrella shape - that's right, umbrella not a weeping variety. my sister's has this maple and it looked stunningly beautiful - unfortunately she doesn't remember the name of the tree.
Leaf shape of coralbark maple rather orthodox (like typical species), likewise habit you describe would fit a normal Japanese maple seedling (or any of various common cultivars) growing in an uncrowded position. Visit a local nursery and see what is on offer, it won't be difficult to find one that fits the bill--where Japanese maples are stocked regularly (over here they are extremely prevalent at present).
