I'm lowered 1.25" in front and 2.5" in the back, and stretched 6"+/-. Technically, extending will raise the rear, but the extra leverage created will actually soften the suspension. So you'll have to lower the rear, and tighten up the spring, or get a different spring. I'm 185-195 (no gear) and find that the stock spring suits me fine. It's a little soft, but it does ok for my riding style.
If you plan to carry a passenger, you will need to either get a stiffer rear spring, or get Soupy's threaded adjustable rear lowering links (or similar) so that you can adjust the height easily when 'she' want's to go for a ride.
Don't forget you'll need an extended chain guard too. So the list is:
Rear:
Lowering Links
Extensions
Chain
Chain guard
Front:
Spacers or
Replacement cover tree or
Replacement full top tree
Exotic Cycle is a sponsor here I believe. I have their stuff and am very happy with them. Gix1300r or something like that makes his own extensions too, and his tuff is great too. I'm sure he'll chime in soon, he is good for finding the extension threads.