Fixed focal length leses tend to be sharper than Zooms I know this one is considered by many to be the best but unsure of the price here is the URL http://www.kenrockwell.com/nikon/300EDIF.htm Those images from Doug look great so maybe thats your choices narrowed down!!

Danny O'Byrne  http://www.digitalartzone.co.uk/

"All the technique in the world doesn't compensate for the inability to notice" Eliott Erwitt