Looking for a real good quality replacement for my 18-135 kit lens (Nikon D80).. I want better quality than the kit lens with the second concern being price. There are so many lenses out there.. I like the 18-135 versatility. Looking to keep that versatility. I also own a Nikon 70-300 VRII lens.. And I'll be picking up a Nikon nifty 50 1.4 within the next week or two. Any suggestions appreciated!