Chocolate Wheat (Stout?) Recipe Help

Kind of patched this together from a few recipes on the forums, wanted some comments as I am new to wheat beers. What are your thoughts on this dark, chocolaty beer? My wife and I like cacao nibs, so I thought they'd be fun to make a beer with.

4lb Alexander's Wheat LME
2lb Briess Pilsen Light DME
3/4lb Chocolate Wheat Malt
1/2lb Briess Blackprinz (have it lying around, ups the color)
1/2lb Caramel 40L

.25oz Cascade @ 60min (I added this because I like a little bitter and I was afraid the recipe was too malty)
1oz Tettnang @ 60min
1oz Saaz @ 5min

4oz Cocoa Powder @ 15min
4Tbsp Cacao Nibs in Fermenter for 2 weeks

Wyeast 1318 London Ale III

Anyway, let me know if you've tried anything like this or see any glaring mistakes, thanks.

It depends what you want, when I think dark and chocolaty I don't think wit yeast. That said the dark malts you are using aren't too roasty/harsh, so it could work nicely. You may need more nibs, when I used them it took a couple ounces to get a noticeable chocolate flavor. I’ve had better luck with cocoa powder since it has had some of the fat removed. I'd probably drop the flaked wheat, it really should be mashed since it is starchy.

Have you used grains of paradise before? I've never seen them used in such large quantities, but I only used a gram in a complex spice bill once.

I appreciate the comments. I recently saw another post using cocoa powder, so I'm thinking a mix of the two would definitely be pleasant. Seems like the Seeds of Paradise would probably be moot, so I can drop those. Given your concerns with the Witbier yeast, is a switch to London Ale III Wyeast 1318 good? Should give some sweet tones I'm looking for. Finally, with dropping the flaked wheat, I thought a Caramel 40L might add some of the sweetness I'm looking for in addition to some flavor, which the lactose would not.