Here I am! I can highly recommend the LiHeat risers. They are taiwan-based but are selling through ebay, if you search for liheat48 you'll find them. They make beautifully shielded cables in black, I personally tested the 200mm version and it works just fine. Apparently someone tested two of their 50cm risers daisychained and still got the card to run with close to no performance impact, quite impressive stuff.
Link to my post with pictures.
Also nicely done for a first build, but cable management and GPU placement have to be revised for the next version. mITX would also be advisable if you're just using a single GPU. We don't want to waste any space, eh?