It's come down to this. I honestly think I've done a great job on this build, considering I didn't even know what a psu was 2 months ago. Lately I've just been going H.A.M. on researching these parts, consistently sleeping after 12 pm X.X.
I still need to pick a psu, and I'm just as crazy about it as this guy.
Regarding the optical drive maybe it's just me but I use mine maybe once a week so I just took a cheap one from ASUS. I use optical drives so little that I still had one bought around 2001 that worked perfectly
Get a Corsair Enthusiast Series TX-650 PSU and be done with it. It's widely regarded as a really good power supply, and gives you a little headroom to boot.
As for a DVD burner, any of the SATA burners in the 20-25 range will do. I like Lite-On, Pioneer, and Asus (which is a Pioneer last time I checked). Stay away from LG. They make shoddy drives that don't really stand up.
A system with a single HD 6850 requires a 500W PSU with one 75W 6-pin PCIe power connector and at least 26A on the 12V rails. This GPU sips power. Amperage on the 12V rail is more important than the total wattage rating of the PSU. The Corsair CX430 with 28A on the 12V rail is sufficient for your build. If you want more power capacity and a top tier PSU then the Seasonic M12II-520 is an excellent deal right now: http://www.newegg.com/Product/Product.aspx?Item=N82E168...