by all means get the 7D if you can afford it...syempre!
also the 15-85IS is way better than the 18-135IS optically how ever much more expensive pud...
if budget is tight get the 17-70 2.8-4 with stabilizer from sigma its so much cheaper with very good optics(better than 18-135). remember 2.8 is the faster zoom usually starts at 50k this is less than half that. macro pud ni siya .22 ra ang iyang min focus distance. and naka hypersonic motor pa gyud. similar to USM sa canon for faster quiet AF.
i have all 3 of these lenses at gizmo drop by try it out, im sure ma impress ka sa 17-70 for its price
here are samples sa 17-70
http://pliki.optyczne.pl/sig17-70OS/sig17-70_fot00e.JPG
Camera: Canon 50D
Parameters: 28 mm, f/4.5, exp. 1/160 s, ISO 100
http://pliki.optyczne.pl/sig17-70OS/sig17-70_fot00h.JPG
Camera: Canon 50D
Parameters: 70 mm, f/5.6, exp. 1/160 s, ISO 200
also i wouldnt get the 270ex though...hold off on that to get the 430exII or di866 instead...even the Di622 for less money would be a more powerful flash and better performance plus af assist beam