This Lego T. rex and Stegosaurus by Sami Mustonen (senteosan) are about as accurate as you can get on a relatively small scale. You may be surprised to learn that both images are actually digital renders. I can only tell the difference because some of the bricks aren’t available in the colors used.
EDIT (AB): Like these? Both the T-Rex and Stegosaurus are on LEGO CUUSOO, where you can vote to have them made into official LEGO sets.
It’s on Lego CUUSOO! Support them cuz they are awesome looking sets!
Tyrannosaurus rex:
http://lego.cuusoo.com/ideas/view/48453
Stegosaurus
http://lego.cuusoo.com/ideas/view/56748
Technically these wouldn’t be predator and prey since they lived almost 90 millions apart. Now if this was an Allosaurus…
Sorry, Nannan…couldn’t resist ;D