I'm a little bigger than you, 6'6" and 260, but I use the Gossamer Gear SpinnTwinn http://www.gossamergear.com/cgi-bin/gossamergear/Spinn-Twinn.html. I am adding beaks on either end, however (see Ray Jardine style) as I still get a little rain splatter because I'm so tall. It runs $175 though, so you may need to look at other options.
The Patrol Shelter by Mountain Laurel Designs is also an option, http://www.mountainlaureldesigns.com/shop/product_info.php?cPath=35&products_id=76&osCsid=4fc4470d8cb8a284d41d637bf150dc24, but again, it runs about $140.
You could always make a SilNylon tarp or even, if you're really daring, a Tyvex tarp to see if you like it before buying. Same goes for the bivy. Making a cheap version before you buy is always a good idea as the bivies are expensive too.