There is a thread about Hexwraiths here:
http://www.dakkadakka.com/dakkaforum/posts/list/423733.page
If you read it you can see that Hexwraiths arn't horrible at all, but have a specialised role that only becomes key later on. I would concur that you should shelve this idea for now.
It looks like you're going for a lot of mobility-which is great
IMO. The Direwolves are decent redirector/blockers, but you need to split them. At this point level, 3x5 would be overkill really-so the suggestion of 2x5 is good and you could always add another unit later on.
The points you saved could be used for lots of good stuff. Being realsitic, I think more core is the way to go, with maybe a Wraith or Banshee hero. If you wanted to remain mobile, then Black Knights would be a better choice than Hexwraiths.While I love the idea of a cavalry army, I really want to re-iterate that,
IMO, you should get more core